This article is jointly authored by Raymond McDougall, David K. Joyce and Ian Nicklin. Except as otherwise credited, all photographs are R. McDougall photos.
Just north of Lake Superior, the Thunder Bay District of Ontario is world famous for its distinctive, ancient amethyst crystals. Thunder Bay amethyst has been known since the 19th century, and is remarkable for its variety – it occurs in all shades of purple from pale to deep, from warm to cool hues, it is often further coloured by inclusions (most often red, due to included hematite) and once in a while phantoms are also found. It is a long journey to the amethyst mines of the Thunder Bay District, and hopefully this article will bring this beautiful region, its history, geology, mines and collecting experience a bit closer!
Location
The Thunder Bay District is located along the northern shore of Lake Superior. The Thunder Bay District is a formal subdivision of the Province of Ontario comprising over 103,000 square km. The amethyst-producing region, within the Thunder Bay District, is located in an area approximately 60 km northeast of the city of Thunder Bay. Just to give you a sense of how long a drive it is to reach the amethyst area from major international centres, it is over 1200 km from Toronto and over 1000 km from Chicago. (Closer large cities are still a surprisingly long way from Thunder Bay: Milwaukee over 900 km, Winnipeg over 700 km and Minneapolis-St.Paul approx. 550 km). Flights from Toronto are frequent, but commercial air travel is not the most convenient when transporting major collecting gear or any decent amount of specimen material.
North of Superior
The land north of Lake Superior is rugged – it is stunning, wild country. It is one of the most beautiful regions in Canada, but because it is relatively remote from major population centres, it is not as well-known or as frequented as some of our more famous scenic locations. It is a land of the Canadian Shield, with exposed Precambrian rock, lakes and evergreen forests.
The distant hills are often quite rounded thanks to the glaciers, and in many places, the shoreline rock has been shaped into smooth forms, first by the glaciers, and since the end of the last Ice Age, by the unrelenting waves, ice rafts and deep frost
Inland from the shoreline, signs of the last glaciation are still readily apparent, with rock faces worn smooth, and interesting features like the deep, dark, round pools known as kettles, created by powerful glacial runoff, carrying rocks as abrasive agents. The most recent glaciers receded from the area approximately 10,000 years ago.
Even beyond the glaciers and away from the shoreline of Lake Superior, this region is constantly being visibly reshaped – by heavy storms, and often just by water as it makes its way from higher land down to Lake Superior.
Speaking of storms, Thunder Bay is named for the sound of the thunderstorms as they roll through. Severe thunderstorms are common throughout Ontario in the summer months, but they are just awesome in Thunder Bay, where the thunder booms around the bay and echoes off the surrounding landforms. (It is an amazing experience. Ideally not experienced in a tent.)
The Thunder Bay District is home to lots of wildlife, including large mammals such as moose, timberwolves and black bears.
From Early People to Modern Times
After the glaciers retreated, the first people moved in to inhabit the lands along the north shore of Lake Superior, approximately 10,000 years ago. Several peoples have lived in this region since that time, the Plano, the Shield Archaic, the Laurel and the Terminal Woodland peoples, and the Anishinaabe (including the Ojibwe, or Chippewa). They have hunted, fished, gathered berries and even mined native copper – and they have been active traders. Early inhabitants used canoes for water transportation – first, canoes were carved out of large tree trunks, and later canoes were made using lighter wooden frames covered by birch bark and assembled using a glue made largely from tree resins (combined with animal fat and soot).
Today, there are few tangible signs of most of these early peoples. In some places, small stone pits and piles of stone are evident, and artifacts have assisted researchers to better understand the past of the area. Painted red ochre pictographs are seen on the Lake Superior shoreline cliffs – these are comparatively recent, estimated to be 200-400 years old.
With the arrival of the first French explorers in the mid-17th century and the opening up of trade by the British and the Hudson’s Bay Company, life around Lake Superior began to change. Through trade, the French and the British engaged with the Ojibwe people. As the British continued to explore and develop these interior regions during the nineteenth century, prospecting and mining followed.
In the beginning, what is now the city of Thunder Bay was comprised of two separate settlements/towns (it was not until 1970 that they amalgamated as Thunder Bay). The first was Fort William, which was established in 1803 by the North West Company as a trading post for furs and other goods. After the merger of North West Company and the Hudson’s Bay Company in 1821, the importance of Fort William as a trading post diminished, although the settlement continued on and became a town.
In the latter half of the 19th-century, a second settlement, initially named Prince Arthur’s Landing, was founded nearby in connection with the Government of Canada’s post-confederation efforts to extend the railway from the Atlantic Ocean to the Pacific. Soon renamed Port Arthur, it was was initially supported by local silver mining. As the silver mining declined, the era of railway development was on the rise, and both Port Arthur and Fort William were to become important Canadian railway towns. Port Arthur was the key rail terminal for Western Canadian wheat, which was then loaded onto ships and transported through the Great Lakes.
Once the first railway across the north of Lake Superior was completed in 1885, trains were the major means of land transportation across the region for the next 75 years.
These same Northern Ontario railways are still fundamental Canadian transportation corridors today, linking Central and Western Canada. The echo of trains in the distance day and night is an evocative sound of this part of the country.
Because the land is so rugged, with steep hills and river gorges, the last section of the Trans-Canada Highway linking Thunder Bay with Sault Ste. Marie (at the eastern end of Lake Superior) took decades to complete and was only finally opened in 1960. Today the Trans-Canada Highway in this region runs like a ribbon through hundreds of kilometers of rocky forest, sometimes relatively close to the lakeshore, and sometimes much further north, where construction was more feasible.
Ancient Geology
The land north of Lake Superior is part of the Canadian Shield, and includes ancient rock types dating back to 2.7 billion years old. The landforms and rocks evidence mountains and volcanoes that have come and gone, and massive geological events including regional structural metamorphism, folding and major faulting.
The amethyst deposits of the Thunder Bay District are associated with the rocks of the Osler Group, formed during a late Precambrian stage of volcanism and faulting, from 1.2 to 0.9 billion years ago. In general, the amethyst deposits are in or near the granitic rocks, in proximity to the contacts between the rocks of the Osler and Sibley Groups. The faulting and related fracturing of these rocks during the late precambrian allowed for the intrusion of the fluids which ultimately led to the deposition of the amethyst crystals. These fluids precipitated the amethyst (and also silver, lead and zinc-bearing minerals at the localities where they occur) onto the walls of the fractures, creating crystal-lined veins and cavities. The faulting and fracturing – and therefore the nature and occurrence of ameythst-bearing veins – differs somewhat from locality to locality within the Thunder Bay District. Some brecciated zones are characterized by large numbers of relatively parallel small veinlets, while in other places much larger fractures are hosted by much more competent rock. The size of individual amethyst crystal-bearing vugs and cavities can vary significantly – they can be as small as 2 cm and a cavity 15 x 3 x 2.4 metres has been excavated. The vugs and cavities within a vein or berated zone are often interconnected with one another.
History of Thunder Bay District Amethyst Discoveries
Silver was discovered in the Thunder Bay District in the mid-19th century and soon silver mines were operating. Amethyst was found in these mines, and was described by W.E. Logan (founder of the Geological Survey of Canada, and namesake of weloganite) in a report in 1846. By 1887, G.F. Kunz was reporting a thriving trade and exports of amethyst from the Thunder Bay District for tourists and for building materials. However, by the early 20th century, two factors led to the decline of the Thunder Bay District amethyst trade: the silver mines began to close and large amounts of high-grade Brazilian amethyst began to appear on the market.
For mineral collectors, the most important amethyst discoveries were yet to come. In 1955, amethyst crystals were discovered northeast of Port Arthur in McTavish Township, but it was the discovery by Rudy Hartviksen in 1967 at Loon Lake (also in McTavish Twp.) that began the modern era of fine amethyst production from the Thunder Bay District. The deposit found in 1967 was to become the Thunder Bay Amethyst Mine, the largest commercial amethyst mine in the region. It has operated continuously since that time and is now named the Amethyst Mine Panorama. Many other localities in the Thunder Bay District have been operated since 1967, and perhaps the most prolific for producing fine, top-quality collector specimens has been the Diamond Willow Mine.
The Diamond Willow Mine
The Diamond Willow Mine works a vein in McTavish Township, in the Thunder Bay District, located on a claim block at the northern end of Pearl Lake. It was named by its owner, Gunnard Noyes, after the type of willow tree that grows at the site of the mine and is highly prized by wood carvers. From the late 1970s and for over 30 years, a section of the vein was leased and worked in the summers by the father-son team of David and Ian Nicklin. They collected with great care and produced some of the finest quality amethyst to have ever come from the Thunder Bay District. The Diamond Willow vein was also regularly worked by Gunnard Noyes, his sons Doug and Clark, and later his daughter Francis.
To give a small insight into what really lies behind the excellent amethysts mined during that time at the Diamond Willow Mine, the following account is written by Ian, together with a few photographs from mining in those days.
Amethyst Mining at the Diamond Willow Mine
My father, Dave Nicklin, and I first met Gunnar on the suggestion of the Ontario Geological Survey regional geologist in Thunder Bay 42 years ago, while on a summer rock collecting trip. Gunnar had worked in the mines at Sudbury for many years and had retired to the small railway stop town of Pearl, approximately 60 km northeast of Thunder Bay. He was a great source of stories and a remarkably generous man. Knowing of the amethyst riches in the region, he staked his several claims just north of the hamlet of Pearl but when we first met him they were not developed to any extent. The claims were only accessible by a narrow twisting trail or by canoe, up Pearl Lake.
On our first visit, my father and I canoed Gunnar’s ancient but still functional Atlas Copco Cobra plugger drill up the length of the lake and met him at the trailhead. I was 16 at the time. Although I was quite strong for my age, I clearly recall complaining about the weight of the drill as I struggled through the bush with it. Gunnar, a man well into 60s at this point, laughed at my complaints, grabbed the drill from me and hoisted it onto his shoulder with no fuss. (Anyone with any familiarity with Cobras knows what that takes and just how uncomfortable it is.) I think he was enjoying showing up the young pup.
We eventually reached a small clearing on an outcrop where there was evident signs of blasting and some amethystine rubble. This was the beginning of the Diamond Willow Mine. Gunnar drilled some holes with the plugger and prepared to put off some shots. He had stuffed some sticks of Forcite 40 into his pockets before heading up the trail. This was the first time we had seen blasting up close and as with most things associated with Gunnar it was memorable. He had some pre-cut fuse and a few blasting caps which had to be crimped onto the fuse with special plyers. In later years, we would use electric caps but these were still early days. He set the charges, lit the fuse (it would burn for about 30 seconds) and told us to find cover … which we did.
As we walked away – never run from an impending blast – to find shelter (with Gunnar yelling “Fire!”, the signal for anyone who might be nearby that an explosion was imminent) I became aware just how long 30 seconds can be. The anticipation of the bang made the seconds interminable. But off they went and I can still see the smoke slowly wafting through the trees and the smell of cordite in the air as we made our way back. And there lay our first amethyst specimens, which I still have to this day. We collected about 100 pounds or so of specimens and packed them into the canoe for the trip back. This was the beginning of a 42-year-long relationship, first with Gunnar and later with his sons.
My father was a teacher and so he had the summers off. While I was in school, we would return to the Diamond Willow every year, collecting for several weeks. Later my father and mother bought a trailer in a nearby camp and spent the summers there – I would join them as time allowed.
We learned how to quarry, drill and blast. Although we used feather-and-wedge method of rock removal as much as possible (to minimize chances of damage), blasting was normally mandatory.
We typically used Forcite 40, which we found to be a good general purpose explosive and usually loaded the holes lightly so as to crack the rock but not throw it to minimize damage to the pockets. It might take a full day of drilling to lay out a blast and I clearly remember not being able to open my hands fully without pain after a day on the plugger.
The amethyst at the Diamond Willow Mine had a complex history of formation, with the crystals first forming tight to the walls of the pockets and then later, probably due to more geologic activity along the fractured fault systems the plates of crystals collapsed into a jumbled mass. At some later time these pockets became filled with a stiff red clay. This history of formation is something of a mixed blessing. If the pockets had not collapsed the crystalline plates would have to be cut or otherwise chiselled off the walls making recovery much more difficult. But of course, because they are collapsed, the plates suffered nearly ubiquitous damage. (Another “fun” aspect of working in the clay filled pockets is that the clay is typically riddled with tiny, razor-sharp quartz shards… after a few weeks of that, your hands are in rough shape…)
Although we have not been back to the Diamond Willow for many years now, today it is still in production.
- Ian Nicklin
Thunder Bay Amethyst
Crystallized quartz in the Thunder Bay District is found in vugs and cavities of varying sizes, from 2 cm across to a cavity large enough that you can crawl in. Donald Elliott (1982) describes one pocket that was 15 x 3 x 2.4 metres in size (references are listed at the end of this post). Amethyst crystals from the Thunder Bay District are most commonly 1-2 cm in size, but larger crystals are also occasionally found. Rarely, very large crystals have been found – a crystal 61 cm across is reported in Elliott (1982).
Thunder Bay quartz crystals occur in many colours and shades, from colourless to smoky quartz, and the variety amethyst occurs in crystals from delicate pale lilac to a deep purple that can approach black. The lustre of Thunder Bay amethyst ranges significantly from the best of the brilliant, lustrous crystals at the Diamond Willow Mine (some of which look perpetually wet (!)) to crystals that are not bright and can even be fairly dull in lustre.
One of the most beautiful and distinctive characteristics of many Thunder Bay amethysts is the inclusion of red hematite (microscopic disks/spherules within the amethyst). The inclusion of red highlights, red zones, and even completely red amethyst crystals are all a classic look for Thunder Bay specimens.
The crystal morphology of Thunder Bay amethyst is basic, as most crystals exhibit only well-developed pyramidal faces. Prism faces are uncommon, and doubly-terminated crystals are rare.
Some specimens are entirely red, and some show distinct zoning – the crystal surfaces are red and amethyst is evident as an earlier phase growth.
One of the authors has always thought the completely red ones look like clusters of jasper crystals, if only jasper crystals existed. (Neither Ray nor Ian has ever contemplated the existence of jasper crystals – both agree that’s a great description of the intense tone of red.) Certain of the completely red crystals have been found to be comprised internally of zoned ametrine, underneath the red outer layer.
The best of the amethyst specimens mined by David and Ian Nicklin at the Diamond Willow Mine are remarkable, in part for their brilliant lustre and exceptional condition.
Labelling Thunder Bay Amethyst
The history of the amethyst discoveries and production of the past is helpful in understanding locality information, particularly for older specimens. it is also instructive for all specimens where the labelling has been vague. It is so common to see mineral specimen labels with “Thunder Bay, Ontario”, and no further information. Although “Thunder Bay amethyst” has actually occasionally been found right inside the city limits, the city of Thunder Bay is not the source of the Thunder Bay amethyst specimens on the contemporary mineral market. Similarly, it would be a feat today to obtain an amethyst specimen excavated in the silver mines of the area before the early 20th century. Unless a specimen is actually known to date to the early 20th century or earlier, specimens labelled “Thunder Bay, Ontario” (or, one sometimes sees “Port Arthur, Ontario” on pre-1970 specimens) are most likely from any of a handful of producing mines and properties – or possibly even any of a rather large number of prospects and additional known deposits – most of which are in McTavish Township, in an area beginning about 50 km northeast of the city of Thunder Bay. Absent specific locality information, the use of only “Thunder Bay” on a label should be considered to refer to the Thunder Bay District.
Thunder Bay Amethyst – Today and Future
Thunder Bay amethyst is among North America’s finest and is known by collectors around the world. These amethysts are contemporary classics for mineral collectors. Because the amethyst-lined vugs of any size naturally have collapsed during their history before anyone has found or collected their contents, excellent quality specimens will always be uncommon, hard to obtain and highly prized.
Amethyst has been found at many localities over a considerable area within the Thunder Bay District (localities up to 200 km apart) and mining continues today at a few properties. As Frank Melanson (2012) points out, thanks to our winters it is a short mining season, and thanks to the rugged terrain, access and access cost is always an issue, so it is difficult to mine Ontario amethyst profitably. And yet, the lure of the amethyst continues to inspire ongoing efforts, despite the economic hardships (and not to mention the black flies!). In Frank’s words, “for many, keeping the mines open was a labour of love.”
It is possible to personally collect amethyst in the Thunder Bay District, primarily on a fee-collecting basis, and also at other prospects and exposures. All of the authors have collected amethyst crystals in the Thunder Bay District. Most individual collecting is typically on the dumps, notably at the Amethyst Mine Panorama, but it is difficult to find collector-quality fine mineral specimens on the dumps. Other collecting is just a bit more involved, as Ian’s description conveys!
When amethyst was first encountered in the early silver mines of the nineteenth century, no-one would have foreseen the story of Thunder Bay amethyst as it has unfolded. Thanks to the later vision and pioneering efforts of Gunnar Noyes, Rudy Hartviksen and others, those first finds of amethyst would lead to the discovery of significant amethyst deposits and the preservation of spectacular amethyst specimens that now reside in museums and collections all over the world. It is unclear how many Thunder Bay amethyst mining ventures will be able to continue in the future, but it is likely that fine specimens will continue to be found, in very small numbers, relative to the amount mined. It is also likely that the best amethysts mined by David and Ian Nicklin will, for a very long time, be considered among the finest quality amethysts ever collected in the Thunder Bay District.
Many, different, beautiful amethyst specimens from this locality are available on both McDougall Minerals and David K. Joyce’s websites; click, here, on David K. Joyce or McDougall Minerals links to go directly to them.
Acknowledgements
Thank you to the Noyes family for their kindness and generosity, and for enabling the development of their deposit such that Diamond Willow Mine amethyst crystals will be enjoyed in collections worldwide for generations to come.
Thanks also to Tory Tronrud and the Thunder Bay Historical Museum Society for kind assistance and permission to share the Fort William mountain train photograph in this article.
References
Elliott, D.G. (1982) “Amethyst from the Thunder Bay region, Ontario” The Mineralogical Record. March-April 1982, vol. 13, no. 2.
Melanson, F. (2012) “Purple Rain: Thunder Bay Amethyst” No. 16: Amethyst, Uncommon Vintage. Gilg, H.A., Liebetrau, S., Staebler, G.A. and Wilson, T., eds. Lithographie, Ltd.
Vos, M.A. (1976) Amethyst Deposits of Ontario Ontario Division of Mines – Ministry of Natural Resources, Geological Guidebook No. 5.
Background
The Tanco Mine is a tantalum-cesium-lithium producer located in Southern Manitoba, Canada, east of Winnipeg. The pegmatite, which does not outcrop to surface, was originally discovered in the 1920’s during a diamond drill program.
Conditions were not right for commercial production until 1969 when Tantalum Mining Corporation of Canada Limited built a 500 ton per day tantalum concentrator was built on the site. Shipping of ceramic grade spodumene concentrate production began in 1986. Cabot Corporation acquired 100% of the operation in 1993. In 1996, the Cabot Specialty Fluids Division started producing cesium brine at the Tanco Mine.
The Tanco Pegmatite
The Tanco pegmatite is a “rare-element” pegmatite of the lithium-cesium-tantalum (LCT) type. LCT pegmatites are mineralogically differentiated from other types by the following:
The Tanco pegmatite is an excellent example of the complex type–petalite subtype of LCT pegmatite.
Geologic Setting
The Tanco pegmatite, situated at the western end of Bernic Lake, is an extremely fractionated, rare-metal, complex type-petalite subgroup, LCT pegmatite and is hosted by a late stage, subvolcanic metagabbro amphibolite. The age of the Tanco pegmatite is approximately 2.576 billion years (Cerny et al, 1996).
The pegmatite is blind or buried and only sub-crops in a limited area in the bottom of Bernic Lake. Based on many diamond drill holes, the pegmatite has a maximum length of 1,990, a maximum width of 1060 metres and is up to 100 metres thick. The total tonnage of the pegmatite is calculated to be approximately 25 million tones (Stilling, 1998)
It is felt that the pegmatitic fluids that formed the Tanco pegmatite were injected into a sub-horizontal joint set with vertical joints enabling the hydraulic “lifting” of the overlying block of metagabbro.
Pegmatite Zonation
Internally, the Tanco pegmatite is composed of nice discrete zones with different mineralization of economic interest –tantalum, spodumene, pollucite and rubidium –each essentially occurring in different zones.
Mining
Mining is carried out using the “room and pillar” method. The excellent ground conditions and the need to utilize selective mining because of the various ores recovered, were the reasons that this mining method was utilized. The “rooms” were originally 16metres square but are now set at 22 metres after years of experience, geotechnical work and careful design.
Mining is mechanized with two-boom jumbos performing most drilling. Occasionally, a single-boom Simba longhole drill is used, particularly in pillar reduction where geometry permits. Ore is mucked and transported using 5, 6 and 7 cubic yard scoop trams and a 20 ton truck. Ores are dumped into ore passes located throughout the mine and then transported by train to the shaft on a tramming level in four-ton Granby style cars. The ores are hoisted to surface via a four ton skip. Mine ventilation is downcast from surface using two fresh air raises. The mine exhaust up casts through the access decline. Air volume required to service the mine is around 5300 cubic metres per minute.
Mineral Processing
The concentrator is constructed on a peninsula of Bernic Lake beside the other mine buildings and offices. All of the ores are crushed down to ,12mm in size. The tantalum, spodumene and pollucite ores are then stored in separate fine ore bins.
Tantalum Processing The tantalum process involves a number of steps and types of equipment. Simply put, the crushed feed is ground to pass 2mm. The <2mm particles are then moved through a series of spiral classifiers, cyclones, tables, belts and filters to produce a concentrate that contains 35-38% tantalum oxides, 14-18% Tin oxide, 5-8% Niobium Oxide and 2-4% titanium oxide.
Tanco’s tantalum concentrates are shipped to Cabot Performance Materials’ facility in Boyertown, Pennsylvania for conversion to the titanium metal or tantalum compounds.
Tantalum is a very useful metal with unique properties. The major uses of tantalum are in the electronics industry and for cutting tools. High quality capacitors are the major single use for tantalum. Tantalum carbide is used in production of hardmetal alloys for cutting tools, mainly in Europe. Other tantalum alloys are important constituents of aero engines as well as in acid resistant pipes for the chemical industry. Tantalum pins are used for medical purposes such as hip-joint replacement, since tantalum is the only metal that is not rejected by bodily fluids.
Spodumene feed at the Tanco Mine is moved through a complex series of processes including heavy media separation, grinding, magnetic separators, cyclones, tables and driers. Concentrated products ranging from 5.00% to 7.25% Lithium are produced in the process.
Most spodumene, today, is used in the manufacture of glasses and ceramics. Lithia is a powerful flux and the lithia component of spodumene can have a dramatic effect on the properties of ceramics, glazes and glasses providing benefits to manufacturers of these products. Effects such as lower viscosity, faster melting and higher gloss enable manufacturers to sped up production, have less flaws (bubbles) and increase the ability to make more elaborate, attractive products.
The other major product made at Tanco mine is cesium formate. Pollucite ore is selectively mined at Tanco along with the tantalum and lithium ores. Tanco mine contains approximately 75% of the known world proven reserves of pollucite. The ore is crushed and ground to -12mm and then dry ground in a ball mill to powder form. With a series of acid/base reactions, the cesium is extracted from the pollucite ore and converted to a high-density cesium formate solution.
Cesium formate is a water clear, water soluble fluid with a specific gravity of 2.3g/cc (two and one third times the density of water). It is used in the oil drilling industry as a drilling fluid where the properties of low viscosity, high specific gravity and complete solution have significant benefits over traditional bentonite/barite drill muds in deep wells greater than 4,575m (15,000 feet!). The cesium formate eliminates formation damage which results in improved hydrocarbon flow from the reservoir in the long term. This means that more hydrocarbons can be extracted from the formation before stimulation techniques are necessary. Cesium formate has low toxicity to people and the environment which is an important added benefit.
Specimen Mineralogy
This section will be concerned with minerals that occur in well formed crystals and/or rare minerals that can be recovered as specimens. It will primarily deal with minerals that I have a first-hand knowledge of. There are many excellent papers on the mineralogy and geology of the Tanco pegmatite if you want greater detail about mineralogy. One in particular is: Cerny, P, Ercit, T.S., Vanstone, P. Mineralogy and petrology of the Tanco rare element pegmatite deposit, southeastern Manitoba, International Mineralogical Association, 17th General Meeting Toronto 1998, Field Trip Guidebook B6. The various minerals will be treated alphabetically.
This section is, presently, rudimentary but I will try and upgrade it as I learn more about the specimen mineralogy and geology of the Tanco Pegmatite.
Albite Albite is ubiquitous at Tanco mine. Normally it is massive to fine grained in many ore types. The spectacular “aplitic albite” which ranges from grey-blue in colour forms wondrous rounded aggregates in contact with massive quartz. Occasionally, well formed albite crystals are found in vugs in the…….zone. The crystals are colourless and often associated with tiny apatite crystals and cookeite.
Amblygonite This mineral occurs in very large crystals at Tanco but, unfortunately, not in fine crystals. It does occur in large rounded white crystals, sometimes with a yellow colour and usually with a montebrasite alteration rim.
Analcime is found in very well formed crystals in cavities in SQUI. The crystals are lithium-rich and lustrous showing the trapezohedral form.
Apatite is present in all zones of the pegmatite but rarely in good crystals. In cavities, it is often found fully or partially coating quartz crystals or the vug walls as beige microcrystals or smooth botryoidal coatings on quartz. Rarely, it is found in cavities as red-purple radiating/rounded aggregates of radiating crystals to 10mm or so in size.
Apatite is often seen as blue blebs, aggregates and rounded crystals throughout the mine.
Arsenopyrite occurs, occasionally, as well formed crystals and crystal aggregates at Tanco Mine.
Beryl The beryl at the Tanco mine, generally is a very white colour, sometimes with a yellowish cast. Beryl crystals at the Tanco Mine are usually simple hexagonal prisms terminated by a pinacoid. They are not generally very elongated compared to beryl crystals from other deposits but, usually do not have a length to width ratio greater than 2:1. Often, the crystals are tabular-hexagonal. In terms of size, beryl crystals at Tanco have been found up to 15cm in diameter and to 30cm in length. More commonly, they are in the 6-7cm diameter range or smaller. The crystals are usually found at the interface between albite and quartz in the Main Zone and are often associated with good grade tantalum ore. Occasionally, the pinacoidal faces of the beryl crystals have a cap or zone of tiny columbite-tantalite crystals on the pinacoidal faces.
The Beryl crystals at Tanco Mine are not uncommon but recovery of specimen-grade crystals is difficult. Because the crystals are always “frozen” in quartz, the quartz must somehow be separated cleanly from the beryl to reveal the full crystal. Most often, the quartz is slightly intergrown with the beryl crystal faces, holding the crystals fast and causing them to shear when an attempt is made to remove the quartz. Occasionally, the beryl faces are smooth and less intergrown with the quartz, enabling the clean removal of the quartz to expose the beryl crystals.
Bismuthinite is not a common mineral at the Tanco mine but does occur on occasion. It occurs as coarse, bright metallic cleavages in quartz albite
Lepidolite is common at the Tanco Mine, although it does not occur in good crystallized specimens. The lepidolite is most commonly in large masses of fine-grained, interlocking crystals. These masses are very compact and actually make excellent lapidary material since they cut well and take a very nice polish. Some local artisans make very nice carvings out of this purple-coloured rock.
Lithiophosphate This is a rare mineral at the Tanco mine but it has been found in excellent, colourless, cleavages.
Lithiophylite is not a particularly common mineral at the Tanco mine but occasionally occurs as large rounded crystals in quartz/albite.
Microlite is another Tantalum-bearing oxide that occurs at the Tanco mine, and in some zones is considered an ore mineral. The only good crystals that I have seen have been colourless, micro-crystals coating titanowodginite crystals in vugs filled with calcite, where the calcite has been leached out with weak acid.
Microcline Microcline is a common feldspar at the Tanco mine but it occurs in UN-commonly sized crystals. As you can see in the image on the right, the crystals of microcline can easily attain lengths of 3-4 metres in size!
Muscovite This Mica Group mineral occurs fairly commonly at the Tanco Mine, most interestingly as rounded “curvilinear” aggregates that mine workers call “ball pien mica”. When in this habit, the muscovite resembles silvery to purple-silvery rounded crystals that do resemble the rounded end of a ball-pien hammer! This muscovite has a high Lithia component and is often referred to as lithian-muscovite.
Petalite is relatively common at Tanco Mine but not in good crystallized specimens.
Pollucite The Tanco Mine is the worlds greatest economic concentration of cesium, due to the very large zone of massive pollucite in this amazing pegmatite. The pollucite is massive, often showing a layered look with clear bands alternating with milky. Unfortunately, crystals of pollucite are not found at the Tanco Mine, except perhaps as micro crystals.
Quartz There is a LOT of quartz at the Tanco Mine particularly in the very large Quartz Zone. Generally, the quartz is massive and white but, occasionally, there are vugs which contain very well formed crystals up to 30cm or so in size. They are usually clear and colourless but can be fairly “smoky, as well. Usually the quartz crystals are associated with drusy pyrite crystals and tiny apatite crystals. Often many of the quartz crystals are actually shards of crystals that appear to have continued to grow after some tectonic event shattered them in the vug.
A very interesting form of quartz at the Tanco mine is the “cleavable” or, actually, “cleaved” quartz. Occurs which is cut by cleavage planes and presents an image of a mineral more like calcite or some other mineral with diagnostically good cleavage. The geologists at the mine love to show this kind of quartz to mineralogical experts and stump them when they are challenged to determine what this unusual mineral is! People are just not used to seeing cleavage in quartz. I expect that the quartz that exhibits this cleavage was thermally or mechanically shocked somehow for it to have these cleavage planes developed so well.
Simpsonite Here is a rare one! In places, at Tanco mine, simpsonite is an ore mineral of Tantalum. It occurs as browny-beige rounded crystals embedded in albite, occasionally as well formed crystals.
Spodumene “Spod” is a key ore mineral at Tanco Mine. While Spodumene occurs in spectacularly large crystals, embedded in quartz or albite, nice “specimen” type crystals rarely occur. Occasionally, smaller, well-formed, terminated crystals occur embedded in quartz and these can make fine specimens. Another interesting occurrence is in vuggy squi where small, gemmy, cm-sized blades of spodumene occur in cavities with analcime.
Tantalite This mineral is one of the main ore minerals of the Tantalum. It occurs in several of the zones of the mine from sparse concentrations to very rich, high-grade zonatons. Generally crystals are small but, on occasion, large prismatic crystals are mined. Some nice specimens of tantalite crystals have been recovered over the years but nice ones are rarely encountered, in recent times.
Tourmaline is common at the Tanco Mine but does not often occur in collectable crystals. The wall zone has lots of black crystals embedded in the feldspar but the crystals are tightly held and rarely can be freed from the other enclosing minerals.
On occasion, very nice pink crystals of tourmaline are encountered embedded in fine grained lepidolite. Specimens of this material can make very attractive specimens.
Tryphylite does not occur in well formed crystals at Tanco but does occur in large, dark yellow crystals embedded in other minerals.
Wodginite Group Several minerals of the Wodginite group have been found at the Tanco Mine. Most interesting in recent times are the excellent titanowodginite crystals found embedded in white beryl and smoky quartz in the “beryl pit” in the main zone. The Tanco mine is the type locality for titanowodginite. The crystals occur as very well formed, doubly terminated, single, wedge-shaped crystals and, more rarely, v-shaped twinned crystals. The single crystals are usually in the 3-4mm size range while the twinned crystals can range up to 20mm in length (rare), making these the largest crystals of this mineral in existence. The crystals are black, often with a curious light iridescent sheen to them.
Wodginite also occurs in radiating clusters embedded in quartz and albite. The wodginite is dark brown and shows a distinctive radiating crystal structure.
Wodginite group minerals are key ore minerals at the Tanco mine. Blobs, patches and particles of wodginite group minerals are common in certain parts of the mine but have little interest as mineral specimens.
By David K. Joyce, Newmarket, Ontario and Roger Poulin, Val Caron, Ontario
Introduction
The Sudbury Mining Area is one of the most prolific metal mining areas in the world. The discovery and development of the mineral deposits are not well known outside of Canada, despite the huge amount of wealth that has been generated by the metal recovery, the contributions to mining technology and, for mineral collectors, the great minerals that have been discovered there. This article is intended to offer a slightly different view of the Sudbury mining area, skewed towards a better understanding of the mineralogy and geology of the area.
History
Before the discovery of minerals in the Sudbury area, the area north and east of Lake Huron’s Georgian Bay was an area mostly used for trapping and logging, as well as subsistence hunting, fishing and foraging by the Ojibway people.
The history of interest in the minerals of the area seemed to start in 1856 when a land surveyor, W.A. Salter, noticed a very strong magnetic anomaly while running survey lines. Salter was running a meridian north from his baseline when he “discovered considerable local attraction, the (compass) needle varying from four to fourteen degrees westerly”. Salter shared his findings with A. Murray of the Geological Survey of Canada, who examined the gossanous rocks near Salters meridian line. Assays of samples returned 2% copper and 1% Nickel but the deposits were too low grade and too remotely located at the time to generate any enthusiasm from contemporary miners. That meridian line ended up being only two hundred metres or so west of the future Creighton open pit mine of INCO Metals Ltd! The two surveyors reported their anomaly findings to the provincial government but their report raised no interest (1917 Royal Ontario Nickel Commission, Pg 20-28). The mining industry was practically non-existent, at the time, in Ontario, or Canada, for that matter. There were simply very few people in Canada who would or could appreciate the potential significance of such an anomaly.
So, as sometimes happens, the eventual, actual re-discovery of more economic mineralization at Sudbury turned out to be a fortuitous incident.
The Dominion of Canada had only come into existence, in 1867. Famously, after Confederation, the government of Canada moved to fulfill terms of confederation with western provinces to build a railway that would run from coast to coast to tie the various provinces and territories, that formed the new country of Canada, together. Such a railway would “open up” the land for development, make it easier for citizens and immigrants to move about and make it easier to administer the new country. Many of the existing provinces and territories had stronger north-south ties to the USA, than they did with the other British colonies-turned provinces. So the railway was begun as one of the largest country building projects in Canadian history.
In 1883, work on the new Canadian trans-continental railway was well underway. During that year, when work crews were blasting cuts through rock for the railway right-of-way, just west of the current location of Sudbury, they encountered a rusty, dense rock. This mineralization, first noted as important by a blacksmith on the railway, Thomas Flanagan, was the first mineralization that spurred interest in further exploration. Land in the vicinity of the discovery was purchased by brothers William and Thomas Murray, Henry Abbott and John Laughrin for $310.00 or $1.00 per acre, the going rate, at the time, for mining concessions.
The discovery led to many other prospectors and developers coming to the area. Prospectors such as Thomas Frood, Francis Crean, Henry Totten and James Stobie showed up and, eventually, all had mines named after them.
The small operations had a difficult time being successful due to lack of capital and the difficult metallurgy of the ores. A turning point came when a capitalist/industrialist from Ohio, Samuel J. Ritchie formed the Canadian Copper Company in 1886 and purchased the Murray, McAllister, Copper Cliff, Stobie and Creighton Mines. The Canadian Copper Company made the Copper Cliff Mine into the first truly successful mining operation. Murray developed the Flanagan/Murray discovery into the Murray Mine, initially as a copper mine. At that time, copper was the commercial driver and nickel was of little interest.
Another deposit was discovered in 1887 and became the Vermilion Gold Mine. It was an unusual deposit for the area since it had significant amounts of native gold and platinum plus a high-grade nickel-copper orebody. Many prospectors flocked to the area to find similar deposits but were not successful.
Canada had no mining or metallurgical infrastructure or expertise, at that time. Early ores were shipped to and processed at the Orford Refinery in New Jersey, USA. Some of the copper ores were very difficult to process due to the presence of “Devil’s Copper” or kupfer-nickel, so named by German miners of old, who had also had difficulty dealing with that impurity metal in their copper ores. There was little use for nickel at the time and it was a nuisance in the way of recovering the more useful copper. The Canadian Copper Company struggled along recovering copper the best it could.
In 1904, the Mond Nickel Company was formed and purchased the Garson, Victoria and Levack deposits to supply its metallurgical facilities. (I remember working in the engineering department at Levack Mine in 1975 and seeing and using old Mond Nickel Company linen drawings of the early mine workings. DKJ) The founder, Ludwig Mond, a chemist from Germany, had developed a process to refine nickel, which was becoming a metal in demand, largely for armament production and industrial applications. The burgeoning growth of industrial development in the developed world, the build-up of military equipment and the eventual breakout of WW I enabled the Mond Nickel Co. to expand and prosper. The Mond Nickel company shipped its matte (NiS/CuS mixture) to its facilities in Wales for further processing and refining.
Thomas A. Edison recognized the usefulness of nickel and came to Sudbury in 1901 to try to try and develop a deposit to supply the factories for his light bulbs. He was not a mining man, however and was not successful.
In 1902, the Canadian Copper Co. merged with the Orford Refinery Co. to accomplish vertical integration. The new company was called the International Nickel Company. That company proceeded to develop a new refinery on the north shore of Lake Ontario in an effort to make processing more efficient. As well, the development of “Monel Metal”, a very useful nickel-steel alloy, spurred the success of the company. Production reached a peak during WWI but after the armistice, production at Sudbury area mines ground to a near standstill. Nickel had become the main metal of commercial interest in the Sudbury operations and, at that time, there were few peace-time uses for nickel.
The year 1928 was a formative year in the history of the Sudbury area. During that year, The International Nickel Company merged with Mond Nickel, to create a future colossus in the world of nickel.
That same year, another American entrepreneur, the famous Thayer Lindsley, formed Falconbridge Nickel Mines Limited to develop the very deposit that Edison had failed to exploit. Falconbridge Nickel was, subsequently, highly successful for many decades from its base in the Sudbury mining area and throughout the world, not just in nickel and copper but in many other metals. Lindsley was a mining giant and a genius.
The Sudbury nickel mining area had difficult times until the mid-1930’s when the world started re-arming. Unfortunately, the early history of success in the Sudbury area was largely tied to military escalation and wars. So it was that International Nickel and Falconbridge Nickel supplied nickel to strengthen steel for the world wars, Korean War, Cold War, Vietnam War and the building of armies and strategic stockpiles by the USA and other counties.
After WWII, many other uses of nickel for more domestic, peace-time consumption were identified. Stainless steel became the norm for many kitchen fixtures, automobile and appliance uses. Sudbury prospered and grew over the years with various ups and downs that paralleled general economic conditions.
As previously mentioned, International Nickel Company and Falconbridge developed mining operations elsewhere in the world and Canada’s dominance as THE world nickel supplier declined. Lateritic nickel deposits, especially developed by those two companies in Dominican Republic, New Caledonia and Indonesia have reduced Canada’s dominance in production of this metal, although it is still an important player.
Eventually, the International Nickel Company of Canada became INCO and the Falconbridge Nickel Mines Ltd. became Falconbridge Limited. The two were at times, fierce competitors and, at other times, business associates that had mining operations on the same orebodies and side by side smelter complexes and that cooperated on matters of efficiency and community development. At times they made overtures to merge but could not overcome the rivalries and ego-driven managements. If the two had merged years ago, a world-class mining/smelting colossus would have resulted. As it turned out, the inability to merge, left them both as relatively vulnerable, relatively small metal producing companies on the world stage. In 2005, Falconbridge merged with Noranda, another Canadian mining/smelting company and the new entity was called Falconbridge. Eventually, in 2006, after bidding wars by INCO, Phelps-Dodge and Xtrata, Falconbridge was taken over by Swiss-based metal company Xtrata, which was later absorbed by its Swiss parent company, metals-giant Glencore.
INCO met a similar demise. It had waited just too long to merge with Falconbridge to form a strong, robust international-scale integrated metals producer. In 2006, Phelps-Dodge, Teck Corp and CVRD of Brazil went after INCO in a series of takeover bids. Eventually Companhia do Vale Rio Doce (CVRD) triumphed and INCO was no more. CVRD changed its name to Vale and the former INCO operations, all fall under that name, now, and are controlled from Brazil.
Interestingly, the metal that started it all is not produced at Sudbury as a finished product, any longer. Copper concentrate is produced at Sudbury but then shipped to Noranda for processing into copper metal. The two big metallurgical complexes of Vale and Glencore continue to operate. Pure nickel metal is produced at Vale’s facilities but Glencore accomplishes final nickel refining at the old Falconbridge refinery, Nikkelraffineringsverk, in Kristiansand, Norway.
Other mining companies operating or recently having mining operations in the Sudbury area are KGHM International Ltd. and Wallbridge Mining Co. These companies have their ores milled and processed by Glencore or Vale on a custom milling-smelting basis.
The Sudbury mining area has produced immense wealth! Here is a tally of one estimate of production from this amazing geological structure (www.Sudbury.com, June 18, 2008):
1.7 billion tonnes of ore containing:
40 billion pounds of nickel
36 billion pounds of copper
70 million ounces of platinum and gold
283 million ounces of Silver
At recent metal values, this represents a value approaching $500 billion produced from over 60 significant mines, over 130+ years! Importantly, though, it is estimated by most that the Sudbury area will be producing metals for the next 100 years or more.
Environmental Impacts: Why the "moonscape" reputation?
The Sudbury Mining Area is often known for its “moonscape” like landscape rather than for the positive impacts it has had on the economy. The main pollutant that has emerged from the Sudbury mining and smelting processes over the years is sulphur. The copper, nickel and other metals are tied up in high sulphur-content ores and, in order to recover the metals, the sulphur needs to be separated from the metals. The early methods to do this were effective but devastating to the environment and, probably, to the health of workers. Prior to 1929, gigantic piles of cordwood up to 2km long(see Figure 5) were laid out and ore was piled on top of the cordwood. The resultant ore-on-wood arrangement was set on fire and allowed to burn/smoulder for months in an effort to drive off as much sulphur as possible before shipping to the smelter. The sulphur was driven off and clouds of sulphur dioxide smoke drifted around the countryside killing all vegetation in the surrounding hills and valleys for miles around. Of course, the loss of vegetation resulted in erosion of the soil. For many decades, the landscape around Sudbury did actually resemble a moonscape! In fact, in the early 70’s NASA had sent some of its astronauts to spend time in the Sudbury basin, as a precursor to conditions they would encounter on the moon.
A more modern smelter complex was built and used after 1929 to smelt the ores but the sulphur dioxide still affected the land around Sudbury. Temperature inversions would cause clouds of sulphur gasses to descend on Sudbury and area, causing further environmental damage, paint to peel from cars, corrosion and who knows what effect on peoples’ health. The answer to the pollution in the 60’s was for INCO Ltd. to build a giant smoke stack, the 381 metre (1250 foot) “Superstack” to take the sulphur gasses higher up to drift away well above the city of Sudbury. The idea was that the gases would become diluted enough before they reached earth again that they would have little effect. It certainly worked for the Sudbury area but “downwind” ph levels in lakes and the environment drifted downward somewhat. When approaching Sudbury by land or air the dominant feature of the skyline was the Superstack with a giant plume of gases coming out of it.
Over the years, the two smelting companies in Sudbury, Inco and Falconbridge, now Vale and Gencore, have spent billions of dollars to actually reduce the amount of sulphur and other gasses that are released to the atmosphere. As a result, now, there is only a barely perceptible plume, if any at all, emanating from the Superstack. In fact, the Superstack has become obsolete. It is no longer needed. It is planned to stop using and tear down the Superstack in the coming years.
What has happened to the sulphur gases? Some percentage of the sulphur has always been captured and converted to sulphuric acid. Now almost all of it is converted to sulphuric acid which is an important chemical in many processes, especially fertilizer manufacture.
The mining companies, local governments and volunteers have spent much money and time re-building, neutralizing and re-vegetating the environment around Sudbury. If you visit Sudbury today, with few exceptions, you would not think of a moonscape. The city is now well forested with more lakes within the city boundaries than any other city in North America. It is a beautiful place again! Well, there are a few places where the barren blackened rocks still dominate but they are fast disappearing as vegetation and forest become re-established. NASA astronauts will probably not visit Sudbury for moonscape training in the future!
Geology
Much has been written about the Sudbury Basin (AKA Sudbury Structure or Sudbury Nickel Irruptive or Sudbury Igneous Complex(SIC)). We will present a summary here, not an in depth treatise. Detailed discussion papers can be found in the following publication:
1984, Ontario Geological Survey, Special Volume 1, “The Geology and Ore Deposits of the Sudbury Structure”.
The Sudbury Structure is a major geological feature on the geological map of Ontario and is located in the Canadian Shield. Originally, geologists believed that molten rock was forced up through the earth’s crust and spread out into a lopolith type of intrusive structure when it encountered the surface sediments. The heavy minerals settled to the bottom of the molten magma forming the nickel-copper deposits that we know today. Other geologists speculated that the Sudbury Structure was a large volcanic caldera.
In the 1960s, a scientist by the name of Dr. Robert Dietz, theorized that a giant meteorite impacted the earth’s crust, breaching it, allowing nickel-rich magmas to intrude close to surface and causing the Sudbury Impact Structure.
The Sudbury Impact Structure is, in fact, a bolide impact structure and is the third largest known crater or “astrobleme” on the surface of the earth. About 1.849 billion years ago, a very large object left outer space and impacted the earth and formed a large crater, the “Sudbury Structure” which, originally, is estimated to have been a circular structure 200km across. Through erosion and various tectonic forces, the remnant of the structure is now reduced and distorted to about 62 by 30km in size.
The early research concluded that the bolide was a meteor and this has been the accepted type of object that created the crater for several decades. Some recent research, analyzing rock types and elemental distributions, concludes that the crater causing object was a comet. Whatever the object was it was BIG and made a large impact on Earth’s crust.
The “fallout” from the impact of the bolide would have been catastrophic. It is estimated that debris from the impact was thrown as far away as 800km and, indeed, rock fragments from the impact have been found as far away as Minnesota. It is also thought that dust and smaller debris were dispersed globally but, of course, have long disappeared due to erosion.
For many years, it was difficult to consider or prove that the Sudbury Structure was, in fact an astrobleme. The 1.85 billion years of deformation and erosion masked the true origin of the structure. Scientists eventually recognized properties and characteristics of rocks in and in the vicinity of the structure that firmed opinions that, in fact, the structure was caused by some sort of impact. Key evidence was the presence of shatter cones, strain features in rocks surrounding the impact, and rocks that were recognized as fallback breccias; rock fragments that were thrown into the air and that fell back to earth and subsequently consolidated into a breccia-like rock. In addition, melted rock formed glass which filled open cracks as dykes beneath the crater. This pseudotachylite rock is known locally as the Sudbury Breccia. These same features can be seen at other major impact sites, both modern and ancient in other parts of the world.
The base of the (SIC) crater forms a layer of brecciated rocks consisting of rock types present from local Proterozoic and Archean rocks. (>2.1ma) This brecciated unit is locally called Granite Breccia and forms the footwall of the crater. The main rock types present are; granite, granite gneiss, gabbro and basalt. Mafic norite also can form breccias layered on and or mixed within the granite breccia. This rock type is termed Sublayer in Sudbury. These two breccia types are the hosts for the copper-nickel orebodies that Sudbury is famous for. Below and at the footwall contact, quartz diorite dykes form concentric and radial dykes rich in copper-nickel-(Pt-Pd-Au) orebodies. Sudbury Breccia occurs as dykes and dyke swarms within the brecciated footwall rocks and can host the rich copper-nickel-(Pt-Pd-Au) footwall orebodies found in Sudbury.
The Sudbury Igneous Complex is the main mineral-bearing part of the Sudbury structure and is considered to be a layered impact melt sheet. That is, when the impact occurred, the basin of the crater filled with a pool of liquid rock composed of mafic norite, felsic norite, quartz gabbro and granophyre from the bottom and up. Only the mafic norite contains sulphides in this group of layered rock types.
Above this unit, the Onwatin Formation is represented by siltstone and at its base, Cu-Zn-Pb-Au mineralization is associated with chert-carbonate deposition. Anthraxolite (hydrocarbon) veins and strong pyrite mineralization is also present. The former Vermilion and Errington mines are examples. This mineralization occurred over time as the SIC lost its heat energy. The very top of the SIC is covered with sandstones of the Chelmsford formation which have a Bouma sequence type of bedding which suggests the SIC was once buried by sediments under an ancient ocean.
Olivine diabase dykes (1230ma) intrude and cross cut the SIC striking north-south and east west. The dykes are vertical and can be 30m wide. From time to time, the dyke contacts can form open fractures containing sulphide, silicate or carbonate crystals.
Deformation is prominent within the SIC structure due to the South Range Deformation Zone which has sheared and displaced all the rocks of the south half of the crater in an average east-west direction. Rare calcite-marcasite, sphalerite and galena can be found in some of these late shear zones.
For many years, it was thought that the only valuable mineral deposits occurred in the Sudbury Igneous Complex as massive or disseminated Cu-Ni sulphide deposits in the granite Breccia Sublayer. In the last couple of decades, though, PGM-Group metal-rich deposits with Cu-Ni have been located in the footwall rocks of the structure to depths of 500m below the SIC contact.
Minerals of the Sudbury Structure
The SIC mineralogy can be divided in 2 distinct categories; The contact Granite Breccia- Sublayer type and the footwall Copper Zone type. Sulphide minerals of the contact ore zones consist of disseminated blebs, breccia fillings, massive veins and irregular bodies. In general, the dominant minerals present are: pyrrhotite, chalcopyrite, pyrite and pentlandite. The Footwall orebodies are usually found near or in Sudbury Breccia vein swarms as disseminated blebs, irregular veinlets and large massive veins several meters thick. Chalcopyrite is the main sulphide and contains, cubanite, pentlandite and minor pyrrhotite, cubanite, bornite, millerite and a variety of microscopic grains of Pt, Pd, Ag, Au, Bi, Te minerals.
(Comment from the Author (DKJ)
When I worked in Sudbury, I saw very few collectable mineral specimens in the various mines. There are massive and disseminated sulphide minerals EVERYwhere but minerals that are “collectable” are relatively rare. The orebodies are mostly massive sulphide deposits mined by bulk mining methods. These types of orebodies and mining techniques are not all that productive or amenable to recovering mineral specimens. Since the modern mining methods are highly mechanized, the ore is often only accessible at stope drawpoints and the ore in the drawpoints in covered with sulphide/rock sludge. It is difficult to see any minerals unless you get a chance to wash down the faces or the muck in the drawpoints. Well crystallized minerals are there, though, and over the years I have come to appreciate what is available through geologists and miners; cubanite crystals, sperrylite crystals, large masses of cleavable millerite, pentlandite crystals “frozen” in pyrrhotite, rare arsenides, cobaltite crystals, native silver in bornite plus many accessory minerals that can be well crystallized.)
Anthraxolite
Common in the lower Onwatin member of the S.I.C. as veins. Also found in the Vermilion and Errington Mines associated with the sulphides in calcite.
Aragonite
Aragonite occurs in limited occurrences in the Sudbury Structure. Some very long crystals, associated with pyrrhotite and cubanite were collected at the Strathcona Mine.
Fluorapophyllite
Fluorapophyllite occurs in the N-W tension fractures that cut through the Sudbury Structure.
Arsenohauchecornite
The Vermilion Mine, in the south-west of the Sudbury Basin, is the type locality for this rare mineral. Excellent crystals have been recovered, in the past but the location has now been largely rehabilitated and it is difficult to recover any interesting mineral specimens. Arsenohauchecornite crystals up to 11mm have been recovered in the past. Usually, they are embedded in pyrrhotite and chalcopyrite, at the Vermillion Mine.
Bornite
Bornite is relatively uncommon in the large massive sulphide deposits and disseminated sulphide deposits that have been the source of most of the metals in the Sudbury Basin. It has been found more commonly in the smaller, high-Cu-Ni-pgm footwall deposits, particularly in the northwest rim of the Sudbury Basin.
Calcite
is not a significant component of the orebodies but can be a significant component of later stage veins, olivine-diabase dykes and open faults cutting some deposits. On occasion, very good crystals have been recovered to 19.0cm.
Chalcopyrite
Chalcopyrite rarely occurs in significant crystals in the Sudbury ores. It is the major source of copper in all types of ores and many, many millions of tonnes of chalcopyrite have been mined in the Sudbury Basin over the past 130 years.
Cobaltite
The Sudbury Basin ores are a significant source of cobalt metal that is recovered as a by-product of nickel smelting and refining. Although the bulk of cobalt content of the Sudbury ores is derived from cobalt in solid solution with nickel in pentlandite, some of the cobalt content of Sudbury ores is derived from cobaltite gersdorffite and other cobalt minerals in the ores. Sharp cobaltite crystals up to 13mm in size have been recovered from the Sudbury Basin, usually embedded in massive sulphides such as chalcopyrite and pyrrhotite.
Copper
Native copper occurred only at the Vermillion Mine in Denison Township, in flat, dendritic crystal groups to 5mm in rock fractures.
Cubanite
Cubanite is thought to be a significant portion of the make-up of the Sudbury Basin ores although it is difficult to quantify. Polished sections of copper ores often show lamellae of cubanite in chalcopyrite in the high Cu-Ni-PGM and massive sulphide deposits. Since it is difficult to visually distinguish cubanite from chalcopyrite in rough ores, the cubanite is often un-noticed.
Excellent crystals of cubanite have been found at the Strathcona Mine, in the 1970s by Mr. Ron Lee, including some very large ones, up to 45mm in length. The cubanite crystals at Strathcona Mine were in cavities on the 2500-2600 levels associated with calcite and pyrrhotite crystals in a large horizontal fracture, near an olivine-diabase dyke.
Galena
Galena occurs in late north-south striking tension veins that cut through the SIC. The veins are 1 to 10cm thick and sometime contain calcite, marcasite, sphalerite and galena crystals. These are more common in the South Range mines.
Gersorffite
Gersdorffite as octahedral crystals and massive mineralization have been noted in the arsenic-rich zones of SIC orebodies, particularly at Garson, Falconbridge and Frood mines. Crystals of gersdorffite have usually been up to few mm.
Gold
Considerable gold has been recovered from the Sudbury ores, over the years, primarily as a by-product of copper recovery and refining. This is largely due to the presence of fine particles of electrum, a natural alloy of silver and gold. Native gold is rarely seen in the Sudbury basin with one exception, at the Vermilion Mine. This mine was precious metals rich and was operated as, largely, a precious metals metals mine. Significant native gold occurred in the Vermilion Mine surface gossan, primarily as sheets and masses in sulphide and carbonate fractures in the host rock.
Magnetite
Magnetite is ubiquitous in the Sudbury ores. It can often be seen disseminated in massive ores as individual, rounded crystals. Really well crystallized specimens have not been recovered.
Marcasite
Marcasite occurs in late north-south striking tension veins that cut through the SIC. The veins are 1 to 10cm thick and sometime contain calcite, marcasite, sphalerite and galena crystals. These are more common in the South Range mines.
Millerite
This mineral is usually found as acicular crystals in most world occurrences. Acicular crystals have been recovered in the Sudbury deposits, as well, particularly at the McLennan Mine, associated with siderite.
Of particular interest, though are the large cleavable masses of millerite that occur in some orebodies, particularly the footwall orebodies such as at Levack, McCreedy and Strathcona mines. Cleavage planes up to 16.5cm across have been noted, which must represent some of the largest millerite crystals ever! Such cleavages are usually embedded in massive chalcopyrite.
Nickeline
Nickeline is usually only present as massive mineralization in arsenic-rich zones of Sudbury deposits, particularly at deposits in the south S.I.C. No crystals of significance have been found to-date.
Pentlandite
Considering the vast tonnages of pentlandite that have been mined in all ore types and processed into nickel metal, at Sudbury, there are no well-formed crystals and anything resembling a crystal rare. It is easy to see small crystals (eyes) of pentlandite embedded in pyrrhotite in higher-grade, massive ores because of the relatively good parting or cleavage that reflects light well. Rarely, individual crystals of pentlandite will form “balls” of pentlandite up to 40mm diameter embedded in chalcopyrite, and other sulphides.
Pyrite
Pyrite is common in the Sudbury District ores but, again, rarely in good crystals. Occasionally, interesting, groups of curved crystals are found in open areas in fault mineralization. Most of the time, the crystals are octahedra up to 30mm, embedded in pyrrhotite and or chalcopyrite. The bulk of the pyrite occurs as grains and thin coatings around pyrrhotite.
Pyrrhotite
Pyrrhotite is ubiquitous in the ores of the Sudbury district and is the major sulphide composing the massive and disseminated ores in the main deposits. Pyrrhotite is rarely recovered in good crystals. It is usually found as massive and disseminated mineralization associated with chalcopyrite, pentlandite, magnetite and gangue mineralization. One massive orebody at Strathcona Mine contained and area with large, enmeshed hexagonal crystals to 20cm.
Quartz
Quartz is a common vein filling in the Sudbury ores but does not often occur in specimen quality crystals. Quartz mostly occurs only as crystals 1-5mm in size.
Silver
Silver occurs in quantity in solid solution, particularly with copper minerals. The copper refineries in the Sudbury District have produced hundreds of millions of troy ounces of silver as a by-product of electrolytic copper refining over the decades. Specimens of native silver or silver minerals are relatively rare, however. One notable occurrence was in a copper-precious metals rich “footwall” deposit at Strathcona Mine where veinlets of native silver were noted cutting through massive bornite and millerite. Superb specimens of “leaf” and “plate” silver, to 35.0cm across in bornite, similar to those from La Mina San Martin, Xacatecas Mexico, somehow survived the mining process.
Sphalerite
Sphalerite occurs in late north-south striking tension veins that cut through the SIC. The veins are 1 to 10cm thick and sometime contain calcite, marcasite, sphalerite and galena crystals. These are more common in the South Range mines.
Sphalerite is also found as fine-grained mineralization, associated with fine-grained galena and gold at the Vermillion and Errington Mines in the Onwating formation.
Sperrylite
Sperrylite Crystals have been found at a number of Sudbury Mines in some quantity but the best specimens have been recovered from the Vermilion, Frood and Broken Hammer Mines.
The Vermillion Mine is the type locality for Sperrylite. A Sudbury chemist, Francis L. Sperry, identified the new compound and in 1889 the mineral Sperrylite was published as a new species. Many, many specimens of sperrylite crystals, mostly embedded n chalcopyrite, have been recovered by geologists and mineral collectors over the years from old mine dumps on the property. These dumps have been re-worked for the precious metals content and the original site of the mine has now been largely rehabilitated with very little to be found now.
The Frood Mine was a huge, operating, underground mine for the past century and access to the mine workings and dumps has not been possible. Regardless, some sperrylite crystal specimens have been recovered and preserved by geologists in precious metals-rich areas of the mine, at various times over the years.
The Broken Hammer Mine was a relatively new and small addition to the past producing mines of the Sudbury District. The deposit was discovered in 2003 and eventually became a small operation producing precious metals-rich copper-nickel ore that was concentrated/refined by a custom mill/smelter. In its short lifetime, the Broken Hammer Mine produced some excellent sperrylite crystals, first from a bulk test-mining of ore and then from a 1.5 year production span. Interestingly, sperrylite crystals from this operation occurred differently from those at other Sudbury District mines. The sperrylite crystals at Broken Hammer Mine were often embedded, not only in sulphide minerals but also in silicate mineralization, usually epidote and/or quartz.
Sulphides: Acanthite, Chalcocite, Hawleyite, Polydymite, Stibnite, Talnakhite, Valleriite, Violarite(tl)
Elements: Bismuth, Electrum
Metallic Te, BI, As Sb: Altaite, Argentopentlandite, Breithauptite, dyscrasite, empressite, galenobismuthite, hessite, mackinawite, maucherite, parkerite(tl), schapbachite, skutterudite, tetradymite, tellurobismuthite, tellurohauchecornite
Platinum Group: froodite(tl), insizwaite, kotulskite, merenskeyite, mertierite, michnerite(tl), moncheite, niggliite, palladian melonite, stanopalladinite, sudburyite(tl)
Other: akaganeite, ilmenite, lawrencite
The majority of the rare minerals listed above were identified from samples collected in the copper rich portions of the various orebodies around the SIC. Copper-nickel massive liquid sulphides can be mobile at temperatures as low as 300C. For this reason a variety of elements such as Au, Ag, Pt, Pd and others were able to differentiate from the contact orebodies and be deposited in favorable structures below the contacts of the SIC and into most of the quartz diorite offset dykes.
Acknowledgements
Thank you so much to friends and colleagues who allowed us to photograph their specimens or to use photographs of specimens in their collections, including Gil Benoit, Tim Jokela, Joe D’Oliveira, Ed and Ruth Debicki, Rod and Helen Tyson, Reiner Mielke, plus Dr. Kim Tait and Ian Nicklin, of the Royal Ontario Museum.
We appreciate being able to use the great photographs of Broken Hammer Mine sperrylite photographs by Michael Bainbridge.
Thanks to Dr. Terry Wallace for allowing us to access the graphics of the evolution the Sudbury Impact Crater by Chuck O’Dale.
All photos by D.K. Joyce unless noted.
References and Bibliography
The Geology and Ore Deposits of the Sudbury Structure. E. G. Pye, A. J. Naldrett, and P. E. Giblin 1984 Ontario Geological Survey Special Volume 1
Harvest From the Rock –A History of Mining in Ontario. Smith, P. , MacMillan of Canada, Toronto, Ontario, 1986
On The Track of the Elusive Sudbury Impact: Geochemical Evidence for a Chondrite or Comet Bolide, Petrus, J.A., Ames D.E., Kamber B.S., Terra Nova, Volume 27, Issue one.
I feel honoured to be associated with and very familiar with Sudbury after many years of working on various project and commercial endeavours.
Levack Mine
I was fortunate to land summer employment in the engineering office of the old Levack Mine, for INCO back in 1975. In those days, Levack Mine was a full mining/milling complex and was in transition from old, labour-intensive mining methods such as “under-cut and fill” and “cut and fill” to more modern methods such as blasthole stoping and vertical retreat mining. The first “vertical crater retreat mining” done anywhere, was done at the Levack Mine in rib pillars. I learned a lot! My job was to be a surveyors’ helper and we went underground each day to survey the advance of development headings and the excavation of stopes. As well, we surveyed in the lines to direct miners on direction and limits of the various blasted excavations. After surveying underground each morning, it was up to surface on the cage, shower, eat lunch and do survey calculations, calculate miners’ bonuses, update drawings and work on simple engineering projects. It was a great job!
I lived in a bunkhouse on Copper Rd., in Levack, that summer, amongst various miners and mill-men. There were a couple of my classmates also living there and we hung out together when not working. I played baseball for “Levack Meats” sponsored by the local butcher shop. Playing rugby for the Sudbury Exiles Rugby Club was a great diversion and we travelled around playing rugby and drinking beer all summer, when not working.
That particular summer, there was a strike at INCO. INCO was famous for fractious labour relations and strikes were often a long drawn out, violent, seething exercise. The day before the strike started, we were called into the chief engineer’s office and told to go back to the bunkhouse, pack enough clothing and personal items for a few days and walk back into the mine that evening. The next day, the strike was on and we were locked in! Only safe way in and out of the mine was by helicopter. A sleeping facility was set up at Coleman Mine, also behind the picket line and a cookhouse was set up at Levack Mine. All of the “management” staff went underground to shut down equipment, ensure pumps were working, be on fire watch, etc. We students worked in the makeshift “cookhouse”, peeling potatoes and carrots, making salads, slinging the food, washing dishes, etc. Whatever “Cookie” and her husband wanted us to do.
During the time, the men outside the picket line threw Molotov cocktails on the lumber yard. A LOT of timber was used underground at that time! Thankfully, the fire was extinguished quickly. The strike got really ugly when one manager’s car windshield was shattered with a baseball bat when he tried to drive it through the picket line. There was a particularly ugly incident where somebody, presumably a union guy, shot at one of the helicopters with a 30-30 rifle! The union men guarded each gateway to the property to ensure none of us management people snuck in or out to visit wives and girlfriends. I recall one union guy, nicknamed “Beancan” due to his habit of eating a can of beans for lunch every day (with the can lid, no spoon) guarded one of the back gates and taped Playboy pin-ups all over the fence and gate!
The strike only lasted 10 days or so. I was in for five days and flown out –my first ever helicopter ride! I learned a lot about management-labour relations during and after that strike. After all of that, all of the union guys got raises immediately after the strike was over AND management did, as well, to match the union wages. All of us students were pretty upset and we gathered en masse at the chief engineer’s office and, essentially were told “Tough!” and dismissed back to our desks.
Anyway, it was a great summer of working, good pay (despite no raise), rugby, beer drinking and freedom from school.
CIL Explosives Ltd in Sudbury. As my last year at the Haileybury School of Mines advanced, I started having job interviews with various mining companies. It was a great time to graduate with multiple jobs opportunities for us all. I enjoyed having job interviews, especially the free lunches and, oft-times, beers that seemed to go with job interviews. I interviewed with INCO and several other mining companies. One opportunity was different. An explosives company, CIL Explosives Inc., wanted some of us to train in explosives technical and sales work. I didn’t want to do that! I wanted to work at a MINE! I decided to go to the interview because some free food and beer could be a partial result. The fellow that interviewed me, Bob Murchie, was an unorthodox interviewer, at least in my very short interviewing experience. I went into the room and here was a guy with his feet up on the table lighting up a cigar! He just talked to me and asked questions that didn’t seem to have anything to do with mining or explosives! In the end he suggested that, if I went to work for CIL, before my career was finished, I would get to visit and work at EVERY mine in Canada. That made me think. Every mine… mineral collecting… Work experience… Mineral Collecting… technical knowledge… Mineral collecting… Sounded pretty good! I thought it was a terrible interview though! A few days later they sent me a telegram saying they would send me a plane ticket to Montreal for a second interview! Montreal! Sure enough the ticket arrived in the mail and I flew to Montreal and had REAL interviews with multiple technical managers, many of whom became great friends in later years.
A few weeks later, a job offer arrived by telegram. I went to the Haileybury railway station to pick it up and was flabbergasted that they offered me a job in Sudbury at the, then, princely sum of $1,200 per month. That was pretty good money for a young fellow in those days. I wrote letters to the mining companies that had offered me jobs, that I could not accept their offers. Upon graduation, I took the bus to Sudbury and was presented with a company car and an expense account. Pinch me! I shared an office with an older Haileybury grad and began my training which seemed to never end. I was always learning.
Sudbury, at that time, was a hotbed of technological innovation, mostly because of INCO and its suppliers. Falconbridge was much more conservative and stodgy. INCO was arrogant but willing to try almost anything to reduce costs, if you could come up with a good idea. I didn’t have any ideas, since I didn’t know much about mining, yet, really. I did work with incredibly innovative scientists and engineers at INCO and CIL and learned a LOT at the “University of INCO”, over two years, that stood me in good stead for the rest of my explosives career. I worked underground at every mine of both INCO and Falconbridge learning the ropes, introducing new explosives and initiation systems and mining methods. It was great!
I helped with the first “virgin” Vertical Crater Retreat mining stope (not a pillar) ever, at Levack West Mine (later called McCreedy West). CIL convinced INCO to try bulk explosives underground so, at Creighton Mine, we loaded a 1.5million ton blast with bulk TNT sensitized, gelled explosives. INCO was one of the first big companies to decide that safety fuse was, in fact, obsolete, both safety and efficiency-wise, so we introduced the brand new NONEL initiation system to all of its mines. We developed new capacitor discharge blasting machines that we sold to many of the mines, or helped them modernize their central blasting systems. INCO decided to totally stop using dynamite and we helped switch them over to EGMN-based water-gelled explosives. We developed shaped charges to make secondary blasting in drawpoints safer and better. It was the perfect time to be an explosives technical service representative in Sudbury.
I am fortunate to have worked on many projects at many of the mines in the Sudbury district including: Levack, Coleman, McCreedy West, Strathcona, Fecunis, Garson, Frood-Stobie, Stobie, Copper Cliff North, Copper Cliff South, Victoria, Crean Hill, Creighton, Whistle and Broken Hammer Mines.
I got married while I was in Sudbury, lived in a couple of apartments and then rented my first house in the “Four Corners” area of Sudbury. It was a happening place at the time with many new, young professionals starting their careers and I made many friends.
I was only based in Sudbury for a couple of years before being moved from coast to coast by CIL. True to their word, I WAS seeing many mines across the country from Vancouver Island to the Island of Newfoundland. I didn’t see them all but most of them!
Eventually, I went to head office and through a series of promotions, ended up being a senior manager in technical, product management and business development roles. For years, I managed the Technical Service Group, a crack group of explosives technical engineers and technologists who could solve any mining, construction, seismic or demolition problem. Many of the technical challenges were in Sudbury and I found myself continuously being drawn back to INCO and Falconbridge operations, at Sudbury, for negotiations, planning, project management and/or technical work. It was still the “University of INCO”!
Eventually, CIL was bought out by our British parent company, ICI, and became ICI Explosives and we acquired the Atlas Powder Company of the USA. That meant I was able to travel the USA and, then, the world acquiring or disseminating technical knowledge and visiting famous mines!
Engineering and Contracting
Eventually, I left ICI Explosives and began a series of positions, mostly in business development for various mining contractors and engineering companies; BLM Group, Dynatec, Aker Kvaerner, Aker-Songer, SNC Lavalin and Aker Solutions. Every one of those positions drew me back to Sudbury. There was no more concentrated center of mining/metallurgical work in North America than the Sudbury area. There were always engineering projects, construction projects, expansions and studies to be done for INCO and Falconbridge and they contracted most of it out.
When I became an adjunct professor teaching “Explosives and Fragmentation in Mining” in the engineering faculty of the University of Toronto, where was the first place that I took my students on a field trip to? Sudbury! The University of INCO. I was able to count on old friends to put on fantastic tours for the engineering students.
I’ve returned to the Sudbury area many times over the years to visit my mineral friends, view their collections, purchase or exchange for mineral specimens, speak at the Sudbury Gem and Mineral Club, etc. I hope this will continue for many years yet!
I was born in Sudbury in 1952 and grew up there. My father worked as a square set stope miner at the #5 shaft of the Falconbridge mine in the town of Falconbridge. In the late 1960’s, a significant production cut was ordered and my father was transferred to the Hardy mine in Onaping. Due to poor road maintenance and conditions at the time, our family moved to the town of Dowling to facilitate traveling to work at the mine.
Dowling wasn’t a very large community and is in the middle of the bush. The best past times I had were fishing, hunting, and generally hiking in the surrounding mountains to pass the time. One day, one of my uncles purchased a car from a man living in River Valley. In the trunk, he discovered two very nice almandine garnets from the River Valley occurrence and gave them to me as a gift. Shortly after this, my father brought home a nice galena cube from the mine to add to my collection. Well now I was hooked! I started collecting micro crystals of galena, sphalerite, calcite, dolomite and pyrite crystals from the Errington and Vermillion mines that were easy enough to get to with my bicycle from my home.
Well it was time to leave home when I turned 18 and as tradition in the Nickel District goes, everyone wished to get hired at the mines with the hope of a long-lasting career. I was hired in 1971 by Falconbridge Ltd. as a labourer at Hardy mine for the summer and in the following 5 years, I held the positions of carpenter helper, crusher man, mechanic, and finally first-class pipefitter helper. I was able to collect some nice minerals from the Hardy mine open pit at this time to add to my collection.
Whenever I was on the Strathcona mine site I would visit the main geology office and sweet talk some of the geologists to donate samples for my collection. Several of the geologists I made friends with encouraged me to think about changing careers and becoming a geologist for the company. On good advice, I left Falconbridge in 1976 to obtain my 3-year Cambrian College diploma of Geology Engineering Technology. In this period of time, I was hired as a field assistant for The Ministry of the Ontario Geological Survey. Working with some of the best geologists in the country allowed me to learn my rocks and minerals very well and foster a deeper understanding of the geology and orebodies of Ontario.
With a diploma in hand, Falconbridge Ltd. hired me in 1979 through 1987 as an underground Beat Geologist and Project Geologist. I was able to work at and collect minerals from Lockerby, Fraser and Lindsley mines. Several layoffs occurred in this period and I quickly organized myself to work private contracts for various companies around the provinces of Ontario and Quebec. I was able to collect many great minerals in the Cobalt silver district and the gold districts in northern Ontario and Quebec.
From 1988 to 2000, Falconbridge hired me again as a Project Geologist. My duties were to discover or delineate orebodies in the Sudbury Igneous Complex. In this period of my career, I obtained my B.Sc. in Geology from Laurentian University in Sudbury in 1990. As a Project Geologist, I was able to work at all the mines in the district and could once again collect minerals from surface dumps and underground at the active mines.
The following exploration projects are some of the larger underground and surface exploration programs I completed personally or with the exploration team in the Sudbury Igneous Complex: Falconbridge, Trillabel, Lockerby East, Denison, Kildream, Creighton, North Star, Lindsley, Manchester Offset, Norduna, Nickel Rim Depth, Nickel Rim, Parkin Offset, Fraser Mine 5W zone, Thayer Lindsley, Craig-Onaping Depth.
Another downturn occurred and I was de-hired by Falconbridge Ltd. In 2000. I updated my consulting business and got busy completing geology exploration contracts for Sudbury District mining companies such as Wallbridge Mining Co. Ltd. and FNX Mining Company, Ltd. to name a few. FNX Mining Company Ltd. hired me in 2003 as an Exploration Geologist to work on their core properties; Falconbridge, McCreedy West, Levack, Kirkwood and Victoria.
FNX was quickly purchased by Quadra FNX and KGHM Polska. Under KGHM my duties included completing all the company mineralogy and petrography projects for the Sudbury area and all the company’s exploration projects around the world. This gave me the opportunity to collect minerals from localities in Chile and Africa.
KGHM de-hired me in 2014 and I am presently retired as a professional geologist. I operate Roger’s Minerals and supply rare minerals to collectors and researchers.
At the present time, my home is filled with mineral specimens from around the world. It all started with those two garnets and has ended in 5,524 specimens collected over a span of 60 years.
Writing this article has made me remember all the friends I made along the way.
Just so that you can visualize them, Here are a few more random photos of mines and scenes from around Sudbury.
In 1969, I was fourteen years old. I was a very keen mineral collector and my brother Brian and I were members of the “Rockids”, the junior arm of the Scarborough Gem and Mineral Club, Scarborough, Ontario, Canada. At that time, there was a dedicated group of adults who organized a meeting for us kids one Saturday afternoon, every month, plus great field trips. The meetings had all kinds of activities, including mineral identification, monthly guest speakers, mineral properties demonstrations, borax bead tests, blowpipe tests, microscopes, LOTS of free mineral samples, displays and activities to take home to work on. I thought the meetings were heaven! I looked forward to them every month.
One of the key features of the club was that, whether they knew it or not, each kid was competing to amass points. Whenever you excelled at an exercise, did well in the What’s’it, the mineral identification contest held every meeting, or even just attended, you received points. The two kids that amassed the most points at the end of each year got to go on a trip to visit a mining operation somewhere in Canada’s north. In 1969, I was one of the two young people selected to visit Steep Rock Iron Mines, at Atikokan, Ontario, all expenses paid by the company.
This was a serious trip! We flew from Toronto to Port Arthur (it has since been re-named Thunder Bay), and then flew in a bush plane, a De Havilland “Beaver”, to Atikokan. You could drive to Atikokan but I think the company figured it would be more of an adventure if we were flown into Atikokan in the small plane. It was! I’d been in a big airplane before but nothing like the Beaver! I was a southern Ontario city boy and I couldn’t believe the extent of the forest, the rivers and the lakes that we flew over between Port Arthur and Atikokan. Of course the pilot buzzed the giant open pit mines and the town before we landed, for the most dramatic impact.
Steep Rock Iron Mines gave us rooms in the Directors Lodge, a big, well appointed, home in Atikokan. I was struck by the red colour of the cars, roads, our shoes and my hands every time I touched something. Fine-grained hematite was EVERYWHERE! A real iron town.
One of the geologists, at the time, was a fellow by the name of Dave Mulder. He was one of our key contacts during the visit. Another was a foreman, Stan ……. something. I’m afraid that I cannot remember Stan’s last name. Dave and Stan took us through the operation from offices, to underground mine, to open pit mines and the mineral processing facilities. They were both great to a couple of 14 year olds.
We looked at all kinds of things. However, all that I really wanted to do, though, was collect minerals! We had a couple of good chances. I recall that Dave Mulder was incredulous that we would want to stop all the time and bash rocks and wrap specimens. “What are you going to do with them?!” And specimens there were! When we visited the ore body at the bottom of what I think was the Hogarth Pit, there was botryoidal hematite everywhere. I picked up some nice pieces. I could have had a lot more but I was shy. Wish I was could re-live that moment! As well, we were turned loose on the waste dumps which seemed, at that time, to be littered with chunks of breccia that were loaded with quartz crystals, calcite and iron carbonate. I bashed, pried and took as much as I could.
We were treated like princes –well fed and watered. I recall sitting with the mine managers one evening, listening to them talk, as they sipped some sort of adult beverages and smoked cigars. I didn’t understand much! At one point I heard one of the men talking about American investing in Canada. Now, I was just a 14 year old, naïve and impressionable. Some may recall that, at that time, Pierre Trudeau had instilled a nationalistic streak in many Canadians and foreign ownership was viewed with suspicion. The Canadian government had even nationalized a number of large “strategic” companies. I chirped in, to the mine managers’ conversation, that “American investment in Canada and control of our companies was a real problem”. Well, did I get an earful! I got a fast lecture on how it was American investors that had put up the money to develop Steep Rock Iron Mines and how American investors were our friends not enemies. I’ve, since, learned a lot about how the capital markets and corporations work but that early lesson still rings in my ears!
We drove back to Port Arthur from Atikokan, a several hour drive. Another learning experience. Along the way we arrived at an accident scene just minutes after a car of native men went off the road and bashed into a road cut. Most of them were dead amongst the rocks and it was the first time I’d seen people dead from such a violent end. The one fellow that was still alive, the driver, was bleeding profusely from his head so we put him in our car and I sat next to him as we sped towards the Arthur hospital. We wrapped his head in spare shirts to stem the blood flow. Along the way we picked up a police escort and sped through all of the lights, dropped him off and then headed for the airport. I don’t recall anything else but I expect our chaperone had to make some kind of statement to the police, since alcohol was involved.
I had loaded up my suitcase with my belongings and LOTS of mineral and ore specimens. For some reason, I was allowed to carry it onto the plane although it was a rather large and heavy suitcase. The stewardesses made me put it at the back of the plane and were amazed at the weight of it. They asked me WHAT was in it and I just replied “Rocks”. They didn’t seem to believe me.
Back home, I was the envy of all of the other kids - SO many nice mineral specimens that I collected. Not many of the specimens have survived. After going to college, moving across Canada, back and forth, probably 15 or sixteen moves, since then, many of the specimens got damaged. As well, when I returned to Ontario, from that trip, I went to the Bancroft Gemboree and traded many of the specimens away. Wish I’d kept them!
We had a ball and I think it was that trip that ultimately led me to a career in mining. Mind you, I decided to go the mining explosives/ engineering/management route rather than the geology route that I had originally envisaged.
Some information about Steep Rock Iron Mines
The mine at Steep Rock Lake was spawned from the dire need for iron ore by the United States during the later stages of World War II. Apparently, German U-boats were sinking a huge percentage of ore carriers from Latin America and the USA wanted to secure more supplies, besides its own mines.
The ores occur in a series of metamorphosed volcanic and sediments that has been tilted almost vertically. There was significant faulting in the area. This deposit is similar and related to the great iron deposits of Minnesota and Wisconsin.
It had been theorized, since the late 1800’s that there was a lot of iron mineralization under Steep Rock Lake.Trouble was, it was only a theory, since only chunks of hematite had been found around the large Steep Rock Lake. Finally, in 1938, many diamond drill holes were drilled to delineate a very large body of iron mineralization. Direct shipping iron ore. It was decided in the succeeding years to drain the lake, divert the river that fed it, dredge the silts and gravels in and around the lake and then mine the iron ore. Steep Rock Iron Mines was formed in 1938 and was listed on the Toronto Stock Exchange later that year. Plans were made to commence the design and building of a mine and ore handling facilities. The war effort and the shortage of iron ore accelerated the entire effort, greatly.
In 1942, Cyrus S. Eaton, an American financier, became involved and steered the efforts to bring the funding to Steep Rock Iron Mines, enabling it to go to production. Two years later, the first ore was shipped to Superior, Wisconsin by rail. In 1945, ore handling and ship-loading facilities were completed at Port Arthur for more flexible shipping to ports on the St. Lawrence Seaway.
The engineering and construction efforts to uncover the deposits and bring them to production were formidable. Lakes had to be drained, rivers diverted and huge amounts of silt and gravel moved. A few facts:
I’m sure that a tremendous amount of environmental damage was done during the rapid development of this operation. I expect that it was partially due to the times and the haste in which it was built. I suspect that it would be have to be done very differently, these days.
Interestingly, another deposit, the Bending Lake Deposit, was supposed to be the next deposit mined by Steep Rock Iron Mines. It turned out to not be feasible, at the time. Still there and others are looking at it.
In 1949, Caland Ore Company was formed by Inland Steel to mine the Caland Property, close by, under lease from Steep Rock Iron Mines. That is where most of the nice manganite crystal specimens came from! It took until 1960 for mining to commence. There was much financing, engineering, permitting and construction to accomplish first!
Summary
I wish Steep Rock Iron Mines was still going. Not only was it a cornerstone of the economy of NW Ontario, it was a source of great mineral specimens. Because of its remoteness, relatively few mineral specimens were recovered. It had the potential to become a “Cave-in-Rock”, “Arkansas” or “Jeffrey Mine” for beautifully crystallized minerals.
Besides my own first-hand knowledge of Steep Rock the following references were helpful.
http://twosox.htmlplanet.com/steeprock/steeprockpage.html lots of good history, photos, etc.
Sona, V.A., Steep Rock Iron Mines, Dredging and Draining of Steep Rock Lake and some of the effects after 45 years. Proceedings of Tailings and Mine Waste ’02, Swets abnd Zeitlinger, ISBN 90 5809 353 0
http://econgeol.geoscienceworld.org/cgi/content/abstract/50/4/373 this has a nice summary of the geology.
If you “Google” Steep Rock Iron Mines, you’ll find lots more information.
Some Additional Images
All specimens are from D.K. Joyce collection, unless noted.
General
For an extended period of time, each year, during winter in Canada, huge deposits of a common mineral, ice, inundate us. The focus of this article is the ice mineralization that encrusts most open bodies of water in this part of the world and its effect on sport fishing activities.
Chemistry
When conditions of pressure and temperature are in a range defined as less than zero degrees Centigrade and pressures of less than 101.325 kPa, significant amounts of the common mineral ice form from the aqueous solutions in the air and on the surfaces of lakes, ponds and rivers. These mineralized deposits are largely H2O with trace amounts of many elements, particularly calcium and sodium. As well, ice crystal deposits often contain inclusions of many organic and inorganic compounds.
Pure ice has a hardness of 1.5 on the Moh’s scale and a density of 0.9167 g/cc. Colour varies from white, colourless, black, blue and green, with many variations, depending on the colour of the underlying water, as well as inclusion colour and density.
Effect on Fishing
During much of the year, access to the surface area of lakes, by foot, is limited to a few metres from shore or as far as a good arm can cast bait with a fishing rod. The only alternative to access further out into the lake is to use boats or canoes, often an expensive, dangerous and cumbersome activity. The advent of ice crusts on lake surfaces, facilitates access to the entire surface area of most lakes by foot. This is a real boon to sport and subsistence fishing (by foot or land-based vehicles), during winter. Of course, it makes access by boat or canoe impossible!
Ice crystals begin forming when water temperature is edged to lower than zero degrees Centigrade by much colder air temperatures and lack of radiant solar energy due to very short periods of daylight. Within a short period of time, the ice crystals merge to form a thin crust which thickens in a relationship directly proportional to air and water temperature. When ice thickness reaches 100mm or more, it, generally, will safely support most human weight. Sub-ice water currents could affect thickness and stability of the ice and are often unpredictable. With appropriate continued air temperatures, ice mineralization will continue to thicken to the point that it will support all-terrain vehicles and even trucks and air-planes on skis. Generally, ice thickness of 0.3 metre are recommended before driving trucks on the ice. Many anglers pull small wooden “huts” or “shacks” onto the ice and leave them there for the duration of the season when ice mineralization is possible.
Ice is a dynamic structure, and behaves much like a horizontal rock structure. Pressures caused by expansion and contraction under temperature and water level fluctuations can cause rifts, cracks and faults (vertical and transverse displacement), all of which can result in dangerous conditions. Often cracking takes place while fishing causing feelings of apprehension amongst novices due to the rather large sound and movements that occur, close by. Generally, cracking of a 0.3m ice layer, although un-nerving is not dangerous. On occasion, non-thinking anglers venture out on areas of ice open on three sides. A large crack on the fourth side can release a large sheet of ice, with the anglers on it, out into the main body of water.
Ice Penetration Techniques
The traditional technique for penetrating the ice mineralization, to access the underlying water (and fish), is to chop a hole through the ice with an axe. Manual augers are commonly used to bore holes of 100-250mm diameter. The author has augured holes, manually, through 1.5 metre in northern Ontario! On occasion, chain saws are used to cut larger holes. Today, serious anglers have gas engine powered augers to facilitate penetration of the ice. These augers make hole production quick and easy.
Fishing Techniques
Methods of fishing through ice mineralization are varied, depending on the region and the species of fish sought. Generally a baited hook is lowered through a hole in ice by short rods, various spools, sticks, etc. The angler simply waits for the fish to attack the bait, sets the hook and then pulls the fish through the ice mineralization via the hole. Easy! Much easier than when there is no ice mineralization to stand on!
Of course, these days, many fisherman use sonar- based electronic instruments to locate fish and increase their chances of catching them.
Summary
The formation of ice mineralization on Canadian lakes results in conditions that enable anglers to travel by foot or wheeled vehicle on the, otherwise, un-accessible surface of those bodies of water. During periods when winter temperatures do not reach adequate sub-zero levels, the ability of anglers to access lake surfaces is limited.
Acknowledgements
I would like to thank my son-in-law Brad Jamieson for the use of his equipment and his guidance in recent ice fishing expeditions. As well, my brother Brian and sister-in-law Mary Joyce who provide tremendous hospitality!
Introduction
I’m new to Arizona. I’ve grown up in and lived most of my life in Canada. That means the desert landscapes, flora, fauna and types of minerals (secondary minerals) of the South-West are all new to me! I’ve travelled much of the world but Arizona is one of THE most interesting, intriguing and satisfying environments that I have encountered (especially during winter and spring!).
Recently, I joined a field trip of the Tucson Gem and Mineral Society, destination; the Red Cloud Mine, north and east of Yuma, not far from the California and Arizona border. I left Tucson and travelled NW on I-10 to Highway 8 and then west on Highway 8 to Yuma for a stay overnight and ready to start early the next morning, heading up highway 95 towards the mine.
I had NO idea what collecting would be like. Actually, I didn’t care. It just seemed like a good idea to visit the Red Cloud Mine which is one of the premier mineral localities of the world. This year, 2019, was the year of the “Wulfenite is Loved” theme at the Tucson Gem and Mineral Show and visions of colourful, well-formed crystals of the AZ-ikonish, lead-molybdate were floating around in my brain. The trip to the mine was important and, if I happened to find some good crystals, that would be a bonus!
I think that I enjoyed the drive from Tucson to Yuma and then to the Red Cloud Mine just about as much as I enjoyed being AT the Red Cloud Mine! This “article” is really a photo-essay showing the road trip to the Red Cloud Mine, a little about the location, collecting and then some of the minerals that I returned with. I’ll show you some of the scenery, flora and minerals that I encountered. Didn’t encounter any fauna! I hope you enjoy it, as well!
About the Red Cloud Mine
The following information has been summarized from Arizona Lead and Zinc Deposits, Part II, Arizona Bureau of Mines, Geological Series No. 19, Bulletin # 158, kindly provided to me by Les Presmyk, an authority on the Red Cloud Mine and "all things Arizona", when it comes to mineral specimens. I’ve added my observations to the information gleaned from the reference.
The Red Cloud Mine was a fairly small mine, as modern mines go. It is located at 750 feet above sea level, near Yuma and the California border with Arizona. It was originally mined during the 1880s and over the years, developed to a depth of 500 feet or so via various shafts, winzes, raises, drifts and stopes. The remnant vein mineralization in the 1950s averaged about 6% lead and 10 troy ounces or so of silver per ton. There were no doubt higher grade sections of the veins, earlier, but few records are available.
The vein occurs in a fault zone and is composed mainly of “limonite”, hematite, quartz, fluorite and calcite. According to the Arizona Bureau of Mines (ABOM) report, there is considerable fault gouge and brecciated rock around the vein. I observed this in the surface exposure of the vein and expect that the underground workings were tricky due to difficult ground conditions. There are many open spaces in the vein material and the openings are often drusy quartz lined. When not filled with iron and manganese oxides the openings commonly contain fillings or crystals of wulfenite, willemite, cerussite, mimetite and calcite. According to the ABOM report, there also can be malachite, vanadinite, smithsonite. Small masses of galena can be found and, presumably in large masses, at times since argentiferous galena was the main ore mineral. Also according to the ABOM report, the galena can be associated with anglesite, cerussite and cerargyrite. As well, the report indicates that the lower workings contained more zinc mineralization than lead, all in secondary minerals. Odd, though. I didn’t see a trace of zinc mineralization during my limited visit.
I was surprised at the number of open spaces in the vein material and the quantity of small crystals of wulfenite, willemite, cerussite, mimetite and hemimorphite. I recognize that I was looking through vein material both in-situ and loose that is the “leavings” of several waves of professional collectors. Still, there are beautiful, small but macro wulfenite crystals to be found and oodles of micro crystals. Roger the resident collector, mentioned further, below, has found some beautiful large and significant crystals and specimens of wulfenite. He spends many hours exploring the workings and has learned where to look. He was very generous with his knowledge and guidance but we were probably not shown the best place to collect on surface and certainly we did not go underground. (I would have loved to!)
Results of Collecting
I was fortunate to find a number of wulfenite crystals, all small but, still, beautiful and classic Red Cloud Mine. They all have that red-orange colouration, sometimes more red and sometimes more orangey. As well, I also found lots of really nice willemite, all sharp micro crystals and all brilliantly fluorescent.
As well, I did find cavities of fluorite crystals. The fluorite crystals are not great crystals and mostly colourless but often serve as substrate for the more exotic minerals. The fluorite has nicely blue-purple fluorescence and adds to the intrigue of the rich willemite specimens. Similarly, there are lots of vugs lined with drusy quartz crystals that sparkle in the strong, ever-present Arizona sun. The quartz druses are often the base for the more rare minerals.
Additionally. I did find a couple of vugs with hemimorphite, mimetite and cerussite crystals. I expect that, if I spent more time at the mine and with the microscope, I’d find other well-formed crystals of various minerals.
Here are some photos of the minerals that I found:
ALL of the Willemite fluoresces a bright green colour like in Figure 46. For some reason, I could not capture that colour through the microscope. All of the micro Willemite photos show the mineral with a ghostly whitish glow.
Other Specimens
Here are some REAL wulfenite crystals and specimens:
Summary
I was delighted to visit the Red Cloud Mine after knowing about it all of my life and after having sold a number of nice specimens over the years. Hopefully, I’ll return there sometime in the future and undertake another attempt to find a larger cavity with some larger, beautiful crystals in it than I found the first time! In the meantime, I hope that you enjoyed the trip to the Red Cloud Mine as much as I did.
Acknowledgements
Thanks to Roger, at the Red Cloud Mine, for his guidance during the visit. I hope that he continues to find great crystals.
Thank you to Les Presmyk for the knowledge that he shared about the mine.
And thank you to Ray McDougall for the use of his photographs.
In 2013, my collecting partner, Ray McDougall, and I had a unique opportunity visit and collect at the Quiruvilca Mine in Peru. Ray is a securities lawyer, on Bay Street, Toronto, and had acted for Southern Peak Mining when they acquired the mine from Pan American Silver in 2012. He had exacted a promise from the president of Southern Peak Mining that he (and I) would be granted an opportunity to visit the mine and collect minerals, sometime shortly after the deal was consummated. Ray contacted Southern Peak about fulfilling the promise, in late 2012, and we made our arrangements to travel to Peru in March 2013. It would be an honour to visit such a famous, classic mineral locality and collect on-site!
The Trip
The first part of the trip was like international travel anywhere; airports, line-ups, security, long overnight flight, busy airports, etc. After landing in Lima we stayed in the airport and caught a flight to Trujillo, the closest city to Quiruvilca. Southern Peaks sent a driver in a spacious SUV to pick us up for the drive to Quiruvilca. Originally, we had planned to stay over in Trujillo and drive to Quiruvilca the next day. We were informed that the new road to Quiruvilca was in very bad shape due to the construction and the very heavy rains that they had been experiencing recently, so much so, that we needed to head up to Quiruvilca the day that we arrived. So we did! The first leg of the road trip to Quiruvilca was pleasant enough on paved road, by the sea shore, through many, many fields of sugar cane. Eventually, we turned up a valley and started to climb into the precipitous mountains that are never far from the narrow coastal plains. The road is only in good shape until Carabamba. After that point it is under construction and is, for several hours, a long, curving, bone jarring, muddy, pothole filled construction site that never seemed to end. The area above and east of Trujillo is a booming mining area with several large mines under development and the old road is a key conduit into the region for supplies, fuel, raw materials, fuel, explosives, equipment and people. As a result, the very heavy traffic on this, currently, pitiful road, through muddy or dusty (depending on the weather) towns, was a constant stream of supply vehicles; buses, cars, pick-ups and tractor trailers. When it is completed, it will be a blessing!
The recent weather did not help road conditions. Above average heavy rains had served to make maintenance impossible, create amazing amounts of mud, induce rock-slides, and cause the heavy traffic to create huge potholes. As a result, progress up the grade to Quiruvilca was slow and dirty, for the most part.
Quiruvilca Mine
Mineralization was first reported at Quiruvulca in 1789. Mining at a corporate level started in 1907 and more or less until 1930 or so. The Quiruvilca Mine has been in continuous operation since about 1940. The nature and grades of the deposit have caused it to alter the types of metals that it has produced over the years from originally copper/silver to copper/gold to the current lead/zinc/silver. The deposit(s) are zoned and the plan view in figure 8 shows the four metallographic zones. The workings are extensive, spread out over a wide area, in many veins. Currently, grades run at about 150 g/t silver, 4% zinc, 1.5% lead and 0.5% copper. Stoping is taking place in, reportedly, 60 places. Considering the 1725 tons/per/day that the mine can process, that is a lot of small stopes! The underground working places are accessed by several adits/ramps and one shaft. Ore is moved to surface, primarily, by one long conveyor belt system but also supplemented by rail movement from ore passes plus skip-hoisted ore. When we looked at a plan of the workings and saw the many, many kilometres of drifts and ramps, we understood why we had to walk so far between stopes!
In essence, the mine is a hodge-podge of several past mining initiatives, haulage methods and development approaches, as is often the case with older mines.
The mining method in the stopes that we observed was remarkably consistent and seemed to consist of a modified narrow-vein, undercut method of mining, necessary due to the incompetent nature of the vein material. Essentially, a raise is driven near-vertically, and compartmentalized to serve as a manway as well as a mill-hole. Ore is blasted and then moved with scrapers and cables from the face to the mill-hole. Rail cars are then loaded from a chute at the bottom of the mill-hole. The stopes are heavily timbered due to poor ground conditions. I didn’t notice any back-filling of completed stopes. In some places, the ore minerals seemed to be high-grade sulphides held together by clay which seemed to have no tensile strength whatsoever.
All to say, I expect that mining costs are probably fairly high but overall costs offset to a payable level by the good grades and low labour costs.
Geology
The geology of the Quiruvilca Mine is fairly simple but interesting. I will “lift” a geological description directly from the book, “Peru, Paradise of Minerals” by Guido Del Castillo, Edited by Art Soregaroli. Those authors relied on geological descriptions by Bartos (1983, 1987, 1990) and Lewis (1956).
The Quiruvilca deposits are in layered volcanic rocks of the Miocene Calipuy Formation which includes andesite and minor basalt flows. The Calipuy formations has an estimated thickness in excess of 2,000m. Intrusive rocks include andesite stocks and dykes.
The ore zones have four distinct zones. Ores in the central part of the district are mesothermal and are dominated by enargite. The mesothermal deposits grade outward to the epithermal deposits. Lewis (1956) described the various zones in some detail.
The inner zone is called the Enargite Zone and, in the past, encompassed the major part of the Quiruvilca Mine. Little mining is done in that zone today. Minerals associated with the enargite in this zone are pyrite tennantite, wurtzite, sphalerite, chalcopyrite, orpiment, galena and rare hutcinsonite.
The second zone outwards is the Transition Zone which is up to 1,400m wide. Its dominant ore mineral is sphalerite with pyrite and tennatite-tetrahedrite. Other sulphides include chalcopyrite, galena, marcasite, arsenopyrite, covellite and wurtzite. Gangue minerals are mostly massive quartz and occasional rhodochrosite and calcite.
The third zone outward is the epithermal Lead-Zinc Zone characterized by sphalerite and galena accompanied by pyrite, chalcopyrite, tetrahedrite-tennantite, marcasite, arsenopyrite and gratonite. Gangue minerals in the lead zinc zone are quartz, dolomite, rhodochrosite and calcite.
The outermost zone is the Stibnite zone. In addition to stibnite, the other minerals there are arsenopyrite, pyrite, sphalerite, galena, chalcopyrite and arsenic.
During our visit, we spent most of our time in the Lead-Zinc and Transition zones.
The Town
Quiruvilca seems to be totally dedicated to the Quiruvilca mine. Some of the mine workings are accessed within town limits and easy walking distance of the town. You can often see miners and workers walking to and from their homes in their working gear. Homes seem to be very modest and crammed into every available space. The Mineralogical Record article by Crowley, Currier and Szenics shows a photograph of the town in 1976 or so and it seemed to be much less concentrated than it is now.
We were very fortunate that Southern Peaks resources invited us to stay in the “Mine Managers house” within the gated/guarded company compound near the mine offices. The compound is a beautiful enclave with nice management homes and bunkhouses, gardens, trees, etc. Our driver would pull up to the gate and a uniformed guard would rush over to open the gate and salute as we passed into the compound. This was repeated on the way out.
The mine manager’s house is like a guest house with seven or eight bedrooms, a couple of bathrooms, washing facilities, dining room and a very nice living room. Marina, a very nice lady, who has worked in the Mine Manager’s house for 30 years making guests comfortable, preparing meals, cleaning and making it a “home away from home”. She was very helpful and hospitable to us, always greeting us with a smile and a welcome. Each morning we would go underground collecting and then come back to the house to get cleaned up and have a late lunch. Afternoons were spent cleaning the minerals and, mostly, reading and chatting by the fire or visiting mine staff to learn about the area.
The mine facilities, including the mine manager’s house were “dry”. All that good food and accommodations were begging to be accompanied by a nice before dinner aperitif or some fine wine during supper but it was not to be.
Very few people spoke English at Quiruvilca (we only met two, the doctor and one manager) so we worked hard, the entire time, with our limited Spanish, to understand, to be understood and make conversation. People were very accommodating and went well out of their way to help us.
Quiruvilca is situated at about 3800 metres (12,500 feet) elevation so the effects of altitude are always apparent. I’ve been “at altitude” many times and always feel light-headed, perhaps with a slight headache and get winded very quickly when climbing or exerting myself. Unfortunately, Ray had a stronger reaction, after a day or so, with racing pulse, nausea, bad headache, etc., so much so that he spent a better part of a day, recuperating and dosing himself with oxygen, under the supervision of the company doctor.
Collecting
Ray and I were allowed to go underground to collect on three days. Geological and production staff were very amenable to accompanying us and leading us through the extensive workings to working stopes. Most of the workings, currently, are in the Zn-Pb-Ag zone, so exotic minerals such as orpiment, enargite, arsenic, etc., were not seen. On the first day, we did encounter a zone of very dark sphalerite crystals associated with some spherical pseudomorphs of galena after, possibly, enargite. Fun to collect.
On the second day, I had a particular thrill. We visited a stope in the Pb-Zn-Ag Zone and encountered a vug containing interesting iridescent, gemmy sphalerite. It was extra fun that the miners and geologists all stopped work to watch me clean out the vug and wrap the specimens. The specimens were not “world beaters” but, as it turns out, each one had with tiny, beautiful, sharp seligmannite crystals associated with the sphalerite. These are significantly different from the seligmannite crystals from La Paloma Mine.
On the third day, we found some sort of botryoidal sphalerite speckled with tiny crystals of tetrahedrite. There were open spaces/cavities in all of the stopes that we visited but most were too small to produce any good specimens. It the old adage that “you have to be in the right place, at the right time” in order to be able to recover good specimens.
The thing is, there is little mining, currently, in the Cu-Ag zone, also known as the “enargite zone” which was the zone that produced the really good enargite crystals, orpiment and hutchinsonite, in the past. The veins that were of the best grades were simply worked out years ago. It seems that the company is going to develop some new workings in the enargite zone which could be good news for mineral specimens. That said, there ARE good specimens being produced at Quiruvilca but in smaller quantities than in the past.
Lima
Lima is a huge, sprawling metropolis with many neighbourhoods. For some reason, the sky is often obscured by a haze that comes in off of the Pacific Ocean so, although it is often sunny, it doesn’t always SEEM sunny. We were fortunate to stay in Miraflores, a relatively well-run, safe, attractive area of the city, right beside the ocean. As a result, we were able to stay in a nice hotel, take pleasant walks along the cliffs in the evening to watch the sun set, eat our meals at sea-side restaurants, etc.
Very civilized! The mineral dealers , in Lima, seem to congregate in an area west of the Plaza San Martin, which just happens to be in one of the more difficult and dangerous areas of Lima. I managed to have my small camera stolen from me, while walking between dealers, by a “pick-pocket” during our two forays there. I wouldn’t have minded so much if the thief had been a little more considerate and left me the memory card with the contained photos! I wonder what she thought when she looked over the images?
Some Minerals
Here are some images of specimens that we collected at Quiruvilca mine or purchased locally or in Lima. Further down are some other specimens of nice minerals from other localities in Peru. They are from Quiruvilca Mine, unless noted otherwise.
More Pictures!
References
CROWLEY, J.A, CURRIER, R.H. and SZENICS, T. (1997) Mines and Minerals of Peru, Mineralogical Record, Vol.28, 21-28
SOREGAROLI, A., DEL CASTILLO, G. (2010), Peru, Paradise of Minerals, Museo Andreas Del Castillo, 55-72
Southern Peaks Mining Website : www.southernpeaksmining.com
I have visited the Bay of Fundy area many times in the past few years, mostly together with my friend and collecting partner Raymond McDougall. We’ve taken lots of pictures, had many adventures, met great people and brought back many specimens for our mineral businesses. My plan was to create an article for my website, like I usually do, to inform people about this interesting area of the world. Ray beat me to it and did SUCH a good job that I can’t see creating my own article. Instead I am providing you a link to his article on his website!
Read Ray McDougall's Article "Nova Scotia Mineral Collecting - The Bay of Fundy" Here
Have a good read! For other reading on collecting minerals in Nova Scotia, have a look at these articles on my website:
I have many interesting and attractive mineral specimens on my website from the Bay of Fundy region. You can look at specimens in the main “Minerals” listing on my site under these headings by clicking on these links:
Or just go to the main “minerals” section of my website and scroll down to “Zeolites, Nova Scotia”!
This listing of mines of the Cobalt-Gowganda area is a distillation of the mines listed in “Silver Cobalt Calcite Veins of Ontario, Ontario Department of Mines, by A.O. Sergiades, 1968. Changes that are known have been added, along with notes of particular interest to mineral collectors. The Lat/Long coordinates have been cross–referenced with current coordinates in the Government database in a best effort to be accurate. If you’d like to get a better visual idea of where many of these mines were, please visit the “Antique Map of the Cobalt Mining Camp” map located in the “Articles” section of this website.
I think that there are certainly errors in this material but, for the most part, there is good information on all of the bigger specimen producers and obscure mines.
Please note that most of these old mines are on private property and that permission needs to be obtained to visit any of them.
Cobalt Area
| Coleman Township | Tr. Oz Ag | Co -lbs |
| Alexandra Silver Mining Company Lat. 47º 22’ 28” Long. 79º 40’ 32” | 3,612,195 | 116,845 |
The Alexandra Silver mine was started in 1906 and became the Canadian Gold and Silver Mining Company in 1913. After two years of operation it was leased to various individuals, until 1962 when Silverfields Mining Corporation began to work it.
During the 1970s and 1980s, Teck Corporation purchased the Alexandra Property and operated it as the Silverfields mine. Teck mined and milled ore from other claims in the Cobalt Camp and operated them all as the Silverfields mine. The main Silverfields mine shaft and mill were near Cart Lake and served as a main source of mill feed. The Silverfields mill, however, also processed ore from dumps, small underground operations, pillar mining operations and as a custom milling operation, until 1983.
| Beaver Consolidated Mines Limited Lat. 47º 21’ 44” Long. 79º 38’ 26” | 7,127,858 | 139,868 |
The Beaver has long been a source of excellent high grade silver/cobalt specimens as well as leaf silver. In the late 1990s, cobalt ore was recovered from both the old Beaver and Timiskaming mines simultaneously from a shaft on the Beaver mine property and so newer dumps on the property are composed of a mix of material from both claims. Collectors may, thus, encounter specimens from the Beaver-Timiskaming mine.
| Brady Lake Property Lat. 47º 21’ 32” Long. 79º 38’ 54” | 2,250,136 | 190,812 |
Actually composed of three original claims; Lumsden, Rochester and Pan Silver. They were operated and separate properties until amalgamated under “Brady Lake Property” in 1947.
| Buffalo Mines Limited Lat. 47º 23’ 36” Long. 79º 41’ 28” | 14,154,558 | 152,406 |
Operated by a number of mining companies and leases, over the years before being acquired by Agnico Mines in 1957.
| Chambers Ferland Mining Company Limited Claim RL401, PCL 3&4 Lat. 47º 24’ 13” Long. 79º 40’ 41” | 2,297,000 | 25,415 |
| Claim RL402W, RL400E ½ Lat. 47º 23’ 53” Long. 79º 40’ 36” | 2,000,000 | 2,057,142 |
These claims were owned or leased by many companies but half of the production was accomplished by Silver Miller Mines Limited between 1954 and 1958.
| Christopher Silver Mines Limited Lat. 47º 21’ 22” Long 79º 38’ 55” | 4,100,000 | 2,143 |
Also known as Columbus Cobalt Silver Company, Cobalt Consolidated and was finally acquired by Agnico Mines Limited.
| City of Cobalt Mining Company Limited Lat. 47º 23’ 35” Long. 79º 41’ 25” | 14,000,000 | 25,022 |
This mine operated right under much of the central part of the town of Cobalt. The old head frame is still standing and currently houses a café. Also operated by Mining Corporation, Cobalt Properties Limited and eventually Agnico Mines Limited.
| Cobalt Badger Mining Limited Lat. 47º 21’ 52” Long. 79º 38’ 58” | 3,475 | 112 |
| Cobalt Lake Mining Company Limited Lat. 47º 23’ 29” Long. 79º 41’ 09” | 6,900,486 | 146,204 |
This property was made up of all of the land underneath Cobalt Lake and was operated by a number of companies over the years.
| Cobalt Lode Silver Mines Lat. 47º 21’ 24” Long. 79º 38’ 39” | 4,493,725 | 2,547,404 |
| Cobalt Silver Queen Limited Lat. 47º 23’ 19” Long. 79º 41’ 52” | 1,406,214 | 168,462 |
| Cobalt Townsite Mining Limited Lat. 47º 23’ 29” Long. 79º 41’ 27” | 32,150,746 | 4,120 |
| Cochrane Cobalt Mining Limited Lat. 47º 21’ 27” Long. 79º 38’ 24” | 33,280 | 2,705 |
| Colonial Mining Company Limited Lat. 47º 23’ 43” Long. 79º 39’ 41” | 1,211,956 | 3,675 |
| Coniagas Mines Limited Lat. 47º 23’ 51” Long. 79º 41’ 22” | 33,963,067 | 310,557 |
When I (DKJ) attended the Haileybury School of Mines, I visited the underground workings of the Coniagas (Cobalt-Nickel-Silver-Arsenic) mine a couple of times to learn how to do geological mapping underground. I recall that the mine manager showed us big chunks of high-grade silver consisting of masses of black, heavy silver arsenide and sulfide mineralization that they were recovering from “pillar-robbing” extraction work.
This claim was operated by W. Trethewey for two years before it was acquired by Coniagas Mines Limited It was bought and sold by a number of companies over the years.
| Conisil Mines Limited Lat. 47º 22’ 12” Long. 79º 39’ 40” | 100,000 | |
| Consolidated Silver Banner Property Lat. 47º 23’ 19” Long. 79º 41’ 52” | 41,701 | |
| Cross Lake O’Brien Property Lat. 47º 23’ 29” Long. 79º 38’ 44” | 2,846,103 | 97,211 |
This property was operated for many years by M.J. O’Brien Limited and then by Deer Horn Mines Limited Specimens may also be referred to as coming from the Deer Horn mine.
| Crown Reserve Mining Limited Lat. 47º 22’ 33” Long. 79º 39’ 33” | 20,325,302 | 33,713 |
This claim consisted of all of the land under Kerr Lake. Spectacular silver specimens have been recovered by mineral collectors in the area of the mine workings.
| Drummond Mines Limited Lat. 47º 22’ 36” Long. 79º 39’ 11” | 3,887,585 | 246,029 |
The Drummond mine was owned by Henry Drummond, a famous Canadian poet. He immigrated from Ireland, attended McGill University and became a medical doctor. He became famous writing poems about the French Canadian Habitant, the rural people of Quebec. He learned about the silver strikes at Long Lake from an assayer at McGill University and headed to Cobalt. He staked a claim just north of Kerr Lake, and operated and managed the Drummond mine until his death in April of 1907. The Drummond Cairn was originally the chimney from his home, beside the mine. It was designated an historical place in the 1930s and more recently was moved into Cobalt from the mine site, near Kerr Lake.
| Farah Mining Company Limited Lat. 47º 23’ 06” Long. 79º 39’ 20” | 8,952 | |
| Foster Cobalt Mining Company Limited Lat. 47º 22’ 22” Long. 79º 39’ 57” | 1,159,390 | 457,574 |
| Hargrave Silver Mines Lat. 47º 22’ 18” Long. 79º 39’ 14” | 506,927 | 6,424 |
| Hiho Mine See Kerr Lake Mining Company | ||
| Hudson Bay Mine Lat. 47º 24’ 15” Long. 79º 41’ 12” | 6,452,266 | 185,739 |
| Juno Metals Corp. Lat. 47º 22’ 59” Long. 79º 39’ 40” | 46,391 | |
| Kerr Lake Mining Company Lat. 47º 22‘ 31” Long. 79º 39’ 29” | 28,502,037 | 650,679 |
This property was worked by a number of companies over the years but famously by the Hiho Silver Mines Limited. Specimens may be referred to as coming from the Hiho Mine.
| King Edward Mining Company Lat. 47º 23’ 33” Long. 79º 38’ 20” | 1,294,233 | 650,679 |
Was also referred to as the Watts Mine in the earliest days of Cobalt.
| La Rose Mines Limited Lat. 47º 24’ 00” Long. 79º 40’ 33” | 26,283,372 | 1,010,720 |
Named for the railroad blacksmith, Fred La Rose, who is credited with finding the first silver at Cobalt. Fred’s original blacksmith shop still stands near the mine site. Since the veins were exposed on the cliff faces at the north end of Cobalt, they are prominent to this day.
| Lawson Mine Lat. 47º 22’ 26” Long. 79º 39’ 41” | 4,213,513 |
One of the veins mined on this property was the famous “Silver Sidewalk”, so called because the surface expression of the vein was almost 1000 feet long and appeared to be a width of about 6-8 inches of largely solid silver.
| Little Nipissing Claim JB2 Lat. 47º 23’ 08” Long. 79º 41’ 44” | 82,000 | |
| Lumsden Claim (See Brady Lake Property) | ||
| Mayfair Mines Limited Lat. 47º 20’ 44” Long. 79º 38’ 36” | 26,240 | |
| McKinley-Darragh Savage Mines Lat. 47º 23’ 19” Long. 79º 41’ 28” | 17,300,000 | 465,582 |
Named for the two men who staked the first claim in the Cobalt Mining Camp. Usually referred to as the McKinley-Darragh Mine.
| Mensilvo Mines Limited Lat. 47º 22’ 29” Long. 79º 40’ 55” | 374,824 | 149,643 |
| Nancy-Helen Mines Limited Lat. 47º 23’ 40” Long. 79º 41’ 26” | 91,770 | |
| Nerlip Mines Limited Lat. 47º 23’ 56” Long. 79º 39’ 09” | 911 | 2,949 |
| New Bailey Mines Limited Lat. 47º 22’ 20” Long. 79º 40’ 14” | 3,131,352 | 76,849 |
Also, popularly known as the “Glen Lake Mine” today. Excellent high grade silver-cobalt ore can still be found in the old dumps at this property.
Nipissing Mines Limited
| Claim 404 Lat. 47º 23’ 33” Long. 79º 40’ 53” | 91,796,735 | 5,641,757 |
| Claim 406 Lat. 47º 22’ 49” Long. 79º 41’ 17” | 1,236,879 | 74,036 |
| Claim 407 Lat. 47º 22’ 51” Long. 79º 40’ 28” | 1,843,633 | 157,738 |
Most mines of the Cobalt area were each located on a single claim or portion of a claim. The Nipissing mine property however was originally staked as four claims, on some of the richest ground in the Cobalt Camp. This explains the extensive workings and large mill site of “the Big Nip”. The many mine dumps have been the source of some nice high grade silver and silver leaf over the years. As well, because of the concentration of veins on the property, very good “Glacial Float” has been located by collectors with metal detectors. These claims were eventually all acquired by Agnico mines and operated along with other claims from the 1960s until the 1980s.
| Nova Scotia Silver Mining Company Lat. 47º 23’ 14” Long. 79º 39’ 44” | 1,082,774 | 114,301 |
| M.J. O’Brien Lat. 47º 23’ 57” Long. 79º 40’ 06” | 43,739,820 | 3,124,504 |
The O’Brien mine yielded some amazing high grade in its heyday. Some of this material escaped the miners and can still be found to this day on mine dumps. As well, the O’Brien had zones that produced good crystals of acanthite pseudomorphs after argentite, proustite and other secondary silver minerals. If collectors encounter well-crystallized specimens of such minerals from this (or any others) mine, they are no doubt very old specimens from the actual mining operations.
| Pan Silver Claim (see Brady Lake Property) | ||
| Penn Canadian Mines Limited Lat. 47º 22’ 32” Long. 79º 40’ 16” | 4,418,802 | 190,821 |
| Peterson Lake Silver-Cobalt Mining Company Limited (Peterson Lake) Lat. 47º 23’ 16” Long. 79º 40’ 33” | 918,076 | 27,328 |
| Peterson Lake Silver-Cobalt Mining Company Limited (Cart Lake) Lat. 47º 22’ 52” Long. 79º 41’ 02” | 5,711,490 | 7,787 |
| Princess Claim Lat. 47º 23’ 16” Long. 79º 41’ 44” | 3,713,806 | |
| Red Jacket Property Lat. 47º 22’ 36” Long. 79º 42’ 20” | 3 | 355 |
| Reinhardt Cross Lake Group Lat. 47º 23’ 26” Long. 79º 38’ 44” | 278,631 | 2,535 |
| Right of Way Mines Limited North Mine Lat. 47º 23’ 52” Long. 79º 40’ 43” | 2,969,195 | 41,811 |
| South Mine Lat. 47º 23’ 22” Long. 79º 41’ 35” |
The Right of Way mine was one of the most prominent mines in Cobalt since it is right beside the railway, in the middle of town. The head frame (North Mine) still stands, today.
| Rochester Claim (see Brady Lake Property) | ||
| Savage Mine (McKinley Darragh) Lat. 47º 23’ 19” Long. 79º 41’ 28” | 4,500,000 | 465,582 |
This mine and the McKinley Darragh mine were both operated by the same company, McKinley Darragh-Savage Mines Limited, during the hey-days of Cobalt from 1903 onwards.
| Silver Cliff Mining Company Limited Lat. 47º 23’ 40” Long. 79º 39’ 20” | 535,246 | 9,323 |
| Silver Cross Cobalt Mining Company Ltd Lat. 47º 22’ 54” Long. 79º 38’ 45” | 3,091 | |
| Silverfields Mine See Alexandra Silver Mining Company | ||
| Silver Leaf Mining Company Ltd Lat. 47º 22’ 33” Long. 79º 39’ 38” | 495,443 | 1,208 |
| Silver Miller Mines Ltd. Lat. 47º 23’ 53” Long. 79º 40’ 36” | 2,030,000 |
This company operated the Brady Lake Property for a number of years. Some specimens may be attributed to Silver Miller mine.
| Smith Cobalt Mines Limited Lat. 47º 23’ 26” Long. 79º 38’ 19” | 456 | |
| Timiskaming Mining Company Limited Lat. 47º 21’ 40” Long. 79º 38’ 27” | 12,118,796 | 202,869 |
This mine has been a very good producer of high grade silver, using metal detectors, over the years.
See Beaver mine for additional info on the Timiskaming.
| Trethewey Silver Cobalt Mines Limited Lat. 47º 24’ 01” Long. 79º 41’ 09” | 7,256,470 | 216,392 |
| University Mines Limited Lat. 47º 22’ 12” Long. 79º 40’ 15” | 790,000 | 82,681 |
| Violet Mining Company Limited Lat. 47º 23’ 52” Long. 79º 39’ 42” | 897,291 |
| Cleopatra Mining Company Limited Lat. 47º 22’ 10” Long. 79º 40’ 29” | 2,160,356 | 136,069 |
Good high grade has been found in recent years in waste dumps around this old mine.
| Provincial Mine Lat. 47º 22’ 36” Long. 79º 41’ 11” | 286,897 | 54,522 |
Interestingly this claim was put aside by the government of Ontario to be mined by a government-controlled company “for the people” something unusual for the time. The mine was opened but operated for only a short time before the ore ran out. It was a money losing venture. The government turned it over to a private company who also failed to make it go.
| Waldman Silver Mines Limited Lat. 47º 22’ 17” Long. 79º 41’ 08” | 33,525 | 2,068 |
| Wyandoh Silver Mines Limited Lat. 47º 22’ 16” Long. 79º 41’ 03” | 33,699 | 1,235 |
| Agaunico and Reuthel mine Lat. 47º 25’ 08” Long. 79º 36’ 17” | 980,000 | 4,353,909 |
The “Agaunico” in this mine's name supposedly stands for Ag-Silver, Au –gold, Ni –nickel and Co –cobalt. The gold may have been wishful thinking. Purportedly, some gold was found at this mine.
| Cobalt Contact mine Lat. 47º 24’ 55” Long. 79º 36’ 59” | 26,000 | 31,028 |
| Dotsee mine Lat. 47º 25’ 41” Long. 79º 45’ 16” | 125 | 8,007 |
| Genesee Mining Company Lat. 47º 24’ 30” Long. 79º 40’ 21” | 69,404 | 12,079 |
| Green-Meehan and Red Rock mine Lat. 47º 24’ 54” Long. 79º 37’ 10” | 498,000 | 27,024 |
| Harrison-Hibbert and Ruby mine Lat. 47º 24’ 53” Long. 79º 37’ 32” | 876,500 | 214,792 |
| North Cobalt and Hunter mine Lat. 47º 25’ 16” Long. 79º 37’ 30” | 1,453 |
| Casey Cobalt-Silver Mines Limited Lat. 47º 34’ 53” Long. 79º 34’ 48” | 10,094,801 | 384,157 |
Also popularly referred to as the Langis mine, after the Langis Silver and Cobalt Mining Company, a company which operated it for a while during the 1960s. The Langis has been the source of some of the best dendritic silver, high-grade ore. Specimens often consist of chunks of ore, sawn to reveal intricate “herringbone” patterns of silver crystals, usually coated with arsenide minerals in carbonate vein material. Sometimes the carbonates can be leached away with acid to reveal excellent herringbone crystal structures. The Langis mine is located on an isolated patch of Cobalt sediments and Nipissing diabase about 12 miles north of Cobalt, at the north end of Lake Temiskaming, near New Liskeard.
| Harmak Mining Company Lat. 47º 34’ 34” Long. 79º 35’ 01” | 4,625 | 12,937 |
| Lang Caswell Mine Lat. 47º 34’ 34” Long. 79º 35’ 01” | 1,503 | 4,932 |
Elk Lake Area
| Roy Silver Mines Limited Lat. 47º 46’ 59” Long. 80º 27’ 46” | 1,888 |
| Ethel Copper Mines Limited Lat. 47º 44’ 53” Long. 80º 16’ 29” | 6,061 | |
| Moose Horn Mines Limited Lat. 47º 44’ 17” Long. 80º 18’ 46” |
The Moose Horn mine was not a prolific silver producer. Only a few tons of silver ore, rich in nickeline were ever shipped. However, the Moose Horn mine was the source of Temiskamite, Ni11As8, which was proposed as a new mineral and was, in fact, a new mineral. Unfortunately, German scientists had characterized maucherite just prior to the characterization of Temiskamite and thus the name maucherite took priority. Temiskamite was subsequently discredited.
| Mother-Lode Mining Company Limited Lat. 47º 44’ 39” Long. 80º 21’ 29” | 1,581 |
| Mapes-Johnston Mining Company Limited Lat. 47º 44’ 16” Long. 80º 26’ 19” | 1,000 | 870 |
| Otisse Mining Company Lat. 47º 43’ 16” Long. 80º 26’ 32” | 2,380 | 26 |
| Shane-Darragh Claim W.D. 904 Lat. 47º 43’ 15” Long. 80º 25’ 20” | 63,417 | 1,214 |
| Lucky Godfrey Silver mines Lat. 47º 39’ 46” Long. 80º 16’ 54” | 9,835 | 593 |
| Cane Silver Mines Limited Lat. 47º 36’ 11” Long. 80º 01’ 29” | 3,100 |
| White Reserve Mines Limited Lat. 47º 26’ 22” Long. 80º 16’ 47” | 19,775 | 452 |
Gowganda Area
The Capitol mine has been a favorite collecting locality for collectors with metal detectors and has produced many fine specimens of dendritic silver ore over the years. Much bulldozer work was done on the dumps and grounds of this property in 2012, which revealed large amounts of high-grade silver ore, much of which has been recovered by collectors with metal detectors. Excellent potential there.
| Castle-Trethewey mine Lat. 47º 40’ 45” Long. 80º 44’ 27” | 9,410,095 | 376,392 |
The “Castle mine”, as it is usually known, still yields nice high-grade and crystallized silver specimens today.
| Miller Lake Everett mine Lat. 47º 40’ 41” Long. 80º 44’ 38” | 3,461 | |
| Millerett mine Lat. 47º 40’ 16” Long. 80º 44’ 34” | 611,822 | 5,004 |
| Bishop, Caleta & Keora mine Lat. 47º 39’ 22” Long. 80º 39’ 28” | 42,400 |
| Hudson Bay Silver Mines Limited Lat. 47º 30’ 47” Long. 80º 48’ 17” | 80,186 | 567 |
This mine, also known as the Rustex mine and Rusty Lake mine, has produced superb specimens of skutterudite. The skutterudite occurs as crystals in calcite veins, with silver and other arsenides. The calcite can be removed with acid to reveal clusters of sharp, lustrous skutterudite with crystals to 0.5 inches in size.
| Bartlett mine Lat. 47º 35’ 49” Long. 80º 48’ 46” | 20,219 | 18 |
| Mann/ Boyd Gordon mine Lat. 47º 37’ 16” Long. 80º 48’ 57” | 123,620 |
Specimens of branching silver crystals in oxidized arsenides have been found over the years at this mine. These specimens are usually said to be from the Manridge mine after Manridge Mines Limited, a company that operated it as well as the Bartlett, Boyd Gordon mines, Reeve-Dobie, South Bay and Welch mines.
| Reeve-Dobie mine Lat. 47º 36’ 11” Long. 80º 48’ 50” | 88,584 | |
| South Bay mine Lat. 47º 35’ 31” Long. 80º 48’ 10” | 1,500 | |
| Welch mine Lat. 47º 35’ 57” Long. 80º 48’ 57” | 1,000 |
| Miller Lake O’Brien mine Lat. 47º 39’ 58” Long. 80º 44’ 01” | 43,181,431 | 787,350 |
This mine has been a source of rich high grade, found with metal detectors.
| Morrisson mine Lat. 47º 39’ 10” Long. 80º 42’ 54” | 719,522 | 22,064 |
| Walsh mine Lat. 47º 39’ 30” Long. 80º 43’ 39” | 453,424 | 3,563 |
Silver Centre Area
The “Woods Vein” of this rich silver producer was also a prolific specimen producer. Most of the mines in the Cobalt area did not contain many open vugs where proustite, wire silver and other rare silver minerals could form. According to Sergiades, 1968, pg. 428, “Pre-glacial weathering on part of the Woods vein extends to 480’ depth; ore deposition in consequence is partly secondary and the vein vuggy.” The collection of the Royal Ontario Museum has excellent specimens of wire silver from the Keeley and Frontier mine as well as superb proustite specimens with well formed crystals to 0.75 inches.
This was a rich mine and superb examples of high-grade ore have been found in the waste dumps with metal detectors.
Note about Silver Centre: When the South Lorrain Silver Mining area was booming starting in 1907, a town called Silver Centre was established. It was a proper town, with a well laid out town site and with great hopes for the future. Unfortunately it did not last. It is considered the area’s “ghost town” and remnants of Silver Centre may still be encountered in what is now wilderness, again. It is mentioned here since collectors may very well run into this name on labels or in writings on the Cobalt area. Interestingly, there is still a road sign in North Cobalt that points people in the right direction and distance for Silver Centre.
Background
There are about 40 limestone and dolomite quarries in south-western Ontario but only a few of them have produced significant mineral specimens. All of them have some vugs of varying sizes with simple calcite or other crystals but only a few have fine, larger, well crystallized minerals such as fluorite, celestine, sphalerite, calcite, marcasite, gypsum, pyrite and pyrite ps pyrrhotite. Rock outcrops are, actually, relatively uncommon due to a thick covering of glacial till but there are also a few miscellaneous non-quarry occurrences of well crystallized minerals in the Paleozoic sediments of southwestern Ontario and I’ll touch on these in this article.
The quarries in south-western Ontario produce limestones, dolostones and shales for a number of purposes such as aggregate, lime and cement production, armour stone, flagstone, building stone and many other uses. Usage is related to the chemical composition and/or physical properties of the rock. Some of the sediments are pure enough for use in chemical or cement plants while others are suitable only as aggregate in concrete, asphalt, road fill, etc.
Geology
The surficial rocks of south-western Ontario were, originally, shallow ocean-marine sediments, laid down in Paleozoic times, and later transformed to limestones, sandstones and shales. Some of the limestones, in turn, eventually underwent dolomitization (changed from, predominately, calcite to dolomite due to percolating magnesium rich brines) (Wolf, 1993) and were transformed to dolomite or dolostone.
Sub-economic concentrations of Mississippi Valley-type lead and zinc mineralization occur in many of the dolostones of the region. Probably about 250 million years ago in geological history, warm brines circulated through metal bearing shales in the sedimentary sequences, dissolving metals such as zinc, lead, sulphur, iron and strontium and eventually precipitated sulphide and sulphate mineralization into voids in the dolostones or even replacing parts of the dolostones. (Wolf, 1993)
Some of the sediments contain hydrocarbons and they can be observed as black bitumen in rock cavities and joints, sometimes enclosing or coating mineral crystals and sometimes included in them.
Amherstberg, Maldon Township, Essex County Unfortunately, this quarry, located just outside of Amherstburg is not currently operating. In the 1970’s, very nice specimens of celestine and calcite were recovered from this operation. The crystals are not large but nice up to 20mm or so. Native sulphur in poor crystals, was also found there.
Beamsville Quarry, Clinton Township, Lincoln County This is another old classic location for south-western Ontario collectors and has been a source of nice sphalerites and calcite specimens for many decades. The sphalerites, up to 15mm, can be beautiful and very orange in colour but are usually red-brown to brown. Many nice specimens of “dogtooth spar” calcite crystals, crystals up to 20mm or so, have been collected here over the years. Fluorites, to 22mm in size, do occur, usually colourless to light lavender but they have not been particularly notable. Galena crystals and other minerals occur here but tend to be small, mostly in the micro range.
Canal Dumps, Niagara Falls Canals for hydro generation at Niagara Falls had to be blasted. Some rock that was blasted from the excavations was trucked away from the site and piled in nearby fields (Wilson M. 2012). The two main accessible rock dumps were adjacent to Lundy’s Lane and Montrose Road in Niagara Falls. Over the years, the rock has been used for various construction purposes, armour stone, rock fill, road construction, etc. Some of the rock, from the excavations was from layers of dolomitic limestone that contained excellent fluorite and sphalerite crystals. Excellent crystals of these minerals can still be found in boulders in the remnants of these rock dumps. You’ll often see these specimens listed from “Montrose Road Dumps” or “Lundy’s Lane”.
The fluorite crystals, arguably, are the most desirable of all of the limestone occurrences in south-western Ontario. The best are ultra-gemmy, lustrous, deep blue or purple and up to 35mm or so in size, although most are less that 25mm on-edge. More commonly, they are light lavender to colourless. The specimens can be extremely aesthetic with the gorgeous fluorite crystals contrasting against the brown, rough limestone. Interestingly, the fluorite crystals exhibit dichroism and change colour depending on the type of light they are viewed in: fluorescent light –blue, incandescent light –purple (Mielke, R. 2012).
The sphalerite crystals can also be very nice here. They range in colour from gemmy beige to gemmy-deep-red or orange and range in size from micro to 30mm.
Some other minerals that can also be found in well formed crystals are calcite(to 20mm), marcasite, anhydrite (aggregates filling cavities to 100mm) and sulphur( less than 5mm) crystals.
Unfortunately, over time, these old rock dumps have been levelled and/or hauled away. This area has become urbanized, with industrial and residential development closing in on the old dumps. During 2011, the last bit of dump was levelled and covered by “big box” stores, thus ending a wonderful mineral collecting opportunity.
Dolime Quarry, Guelph: This quarry has only become popular in recent years and has become a source for nice sphalerite crystals. I, personally, have not collected at this quarry but have seen some excellent specimens with large, complex sphalerite crystals to 50mm across, associated with small calcite crystals. The crystals are usually a dark brown to bright orange to dark-brown with good lustre. Some sphalerite is gemmy and has been facetted.
Douglas Point: When the nuclear power station was built at Douglas Point, rock was excavated for some of the facilities. The excavation of the spillway for water from the plant revealed cavities of well-formed, gray celestine crystals to 50mm or so. This was a one-time occurrence and the time to collect was short so only a relatively few specimens were recovered.
Flamboro Quarry, West Flamborough,Wentworth Co.: The geology and mineralogy at the Flamboro Quarry is very similar to that of the Lafarge Quarry (described below). They are only a few hundred metres apart and are working in exactly the same strata - Silurian dolostones of the Guelph and Lockport formations. However, there are subtle differences between the two quarries. In general, the sphalerite at Flamboro seems more lustrous and gemmy than the sphalerite at Lafarge. As well, the fluorite crystals at Flamboro can be a bit more brownish, sometimes with an outer phase of light lavender fluorite while this is less common at Lafarge. At the time of writing, the quarry is closed on weekends and, thus, no collectors are allowed to collect. This has effectively shut down organized collecting at the Flamboro quarry.
The fluorite crystals from this quarry can be superb. They are simple cubes to 30mm, clear to colourless but usually tinted brownish, possibly due to inclusions of hydrocarbons. The crystals can be found as single crystals on matrix, scattered crystals and clusters on matrix and as tightly packed crystals lining vugs. Fluorite at Flamboro quarry is often associated with orangey-brown sphalerite crystals. As at Lafarge quarry, the fluorite is usually in large boulders of very hard rock and recovery can be difficult.
The sphalerite at this quarry can be fabulous. It is commonly found as smaller, 2-5mm crystals but can also be found in gemmy, complex, twinned aggregates to 100mm in size. Colour ranges from pitch black to a gorgeous burnt-orange colour.
Recently, very nice galena crystals have been found at Flamboro with well-formed crystals up to 25mm or so. Crystals usually show the cube as the predominate form but some are modified by octahedral and dodecahedral faces.
Modest specimens of calcite(to 60mm), gypsum in complex crystals to 1400mm, marcasite to 15mm and other minor minerals have also been found at the Flamboro Quarry. Interesting round “balls” of calcite crystals to 10mm, or so, are often found at this quarry. Despite its proximity to the Lafarge quarry, celestine crystals, to my knowledge have not been recovered there.
“Forks of Credit” Area: In this area, there are or have been a number of quarries and natural exposures that expose layers of limestone that have open spaces filled or partially filled with bright orange celestine at the contact between the Lockport dolomites and Whirlpool sandstones (Sabina, 1965). Why is it orange? Maggie Wilson pointed me to the American Mineralogist, Volume V64, p160-168, 1979 which explains that the orange colour in celestine is caused by the presence of copper (Wilson, M 2012 ). Single crystals are rare and vug fillings tend to be semi-radiating, closely compacted aggregates up to 100mm or so. I’ve not seen well terminated crystals from this location and single crystals tend to “bridge” vugs. The specimens are unique and there is usually one in most southern Ontario collectors’ collections. Some small marcasite and calcite crystals are sometimes associated with the orange celestine. At some locations, particularly the Deforest Quarry, the presence of significant copper has resulted in malachite being formed, sometimes in micro-crystals (Wilson M., 2012).
High Falls, Manitoulin Island: Interesting geode-like nodules were once available from the Paleozoic sediments at High Falls on Manitoulin Island. These nodules are sometimes hollow and are lined with crystals of calcite, dolomite, celestine and chalcopyrite. Apparently, there is an overhang of rock at the site, which can be very dangerous. I am told that the locality was exhausted many years ago and is currently off-limits to collecting on private land (Benoit G. 2012, personal communication).
Inverhuron: Very well formed crystals of calcite occur in cavities in limestone on the shore of Lake Huron, just north of the town of Inverhuron, Ontario The strata with the calcite crystals is at lake level or below high water level most years. When the water level in Lake Huron is low, the strata with the crystals is at or just above the water level and then it is fairly easy to access them. The calcite is unique and shows twinning on 0001 plus interesting hoppered faces. The best crystals occur in clay filled openings and they are gemmy and clear. Crystals that occur in openings not filled with clay tend to be slightly frosted. As well, balls of radiating white strontianite crystals to one centimetre occur with the calcite in some areas. There are a couple of zones where 10mm or so sharp, icy-blue celestine crystals can be found. Unfortunately, the occurrences are now within the boundaries of an Ontario Provincial Park (Inverhuron) and collecting is probably not allowed.
Lafarge (Dundas) Quarry , Wentworth County: This quarry has had several owners over many decades and has been known variously as the “Dundas” , Redlands, Steetley and, most recently, the Lafarge Quarry. It is the “grand-daddy” of the quarries and has operated for many decades. It is huge in size and is really composed of three large excavations, two of which are finished. The quarry started out on the south side of Highway 5 but a new quarry was started on the north side of the road and connected by a tunnel blasted beneath the road. Rock is now blasted and crushed in the third quarry and transported south to the distant processing and shipping plant by overland conveyor.
People, beginners and seasoned collectors, have been visiting this quarry to collect fine mineral specimens for many decades. There are various types of open spaces where well-formed crystals occur. Many of the open spaces are stromatolites or other fossils, while others are random openings or faults/joints in the limestone. The “vugs” can be up to 2m across! These openings are the favourite place to find excellent celestine, fluorite, sphalerite and calcite. There are many veins of calcite up to dozens of metres long that cut through the limestone, many of which are large and contain abundant openings of calcite. There are also veins of sulphides (marcasite, galena and sphalerite) that are fairly massive, in a couple of places in the quarry.
The Lafarge quarry is probably most famous for the celestine crystals that occur in the lower layers of rock at the quarry. Quarrying is not always done in the lower layers strata and so celestine is not always available. Long stretches have gone by with no celestine being found. The celestine crystals are found in many habits including large simple prisms to 150mm, large prisms with multiple terminations, small, milky, doubly-terminated prisms, scattered on matrix and smaller gemmy doubly-terminated crystals. Colour ranges from colourless to milky white to sky blue and crystals can be highly lustrous or dull-opaque. The larger crystals are almost always loose in the pockets having been jarred from the vug walls by blast vibrations. The larger crystals almost always have micro marcasite crystals included in them and, on occasion have calcite or galena crystal on their surfaces. Celestine sometimes occurs with gypsum.
The fluorite at this location tends to be amber to colourless, simple cubic crystals up to 100mm on-edge but normally more like 10-30mm or smaller in size. Lustre is usually excellent. The crystals are, however, often in tight vugs in the hardest rock in the quarry and so can be very difficult to extract intact. Fluorite is often found in the long rows of armour stone that is set aside for use in breakwaters or other barriers. Fluorite occurs, most commonly with sphalerite, marcasite and calcite. Interesting specimens have been recovered showing fluorite crystals embedded in hard, black hydrocarbon.
Sphalerite is usually red-brown to brown to black and almost always in complexly twinned crystals to 35mm or aggregates up to 100mm or so across. It occurs with fluorite, calcite and marcasite crystals. Sometimes the sphalerite crystals can be highly iridescent. Some sphalerite is gemmy and has been facetted.
Galena is a relatively rare mineral at Lafarge quarry, at the present time. Although it does occur in crystals up to 25mm usually it is in crystals less than a few mm. In the 1960’s, a thick vein of sulphides was exposed in the south quarry and excellent specimens of galena crystals to 10mm, or so, on marcasite or sphalerite were recovered by R. Mielke and his father (Mielke, R. 2012, personal comm.). Unfortunately, the marcasite from this vein occurrence is not stable. Crystals of marcasite on limestone, to date, seem stable (Mielke, R., 2012)
Gypsum is rarely (relatively) found at this quarry in large water clear crystals in limestone vugs. The crystals usually fill all or much of the void and well terminated crystals are not common. Large, up to 120mm, highly striated part crystals are more commonly recovered. Gypsum can occur with celestine and interesting specimens have been recovered with celestine crystals fully embedded in the water clear gypsum.
Recently some sharp marcasite pseudomorph after pyrrhotite crystals up to 2cm have been found but these are rare. Excellent “cockscomb” marcasite and individual crystals of marcasite to 20mm have been recovered. Other minerals that are occasionally found include strontianite in white botryoidal crusts and micro crystals and micro sulphur crystals.
Collecting status at this quarry is currently in jeopardy. Safety infractions by people on organized club-field trips in the past few years have strained relations with the quarry management and collectors are worried that they may not be allowed to visit this amazing old quarry. Let’s hope that this does not happen. It would be a tragedy to lose collecting privileges at this prolific site. Walker Brothers Quarry, Niagara Falls: The Walkers Brothers Quarry was a stalwart specimen producer many years ago and nice specimens are still seen from time to time on the swap tables. It was well known for its water clear gypsum crystals, creamy, curved dolomite crystals and small sphalerite crystals.
Collecting
It is possible to collect at some of these localities but collecting is usually limited to organized Gem and Mineral Club field trips at the operating quarries. The big quarries are operated by multinational companies who take trespassing and safety very seriously! You should endeavour to join a club in the area and then it will be easy to be notified of and participate in field trips when they occur.
Mineral Specimen Images
These are the most visited mineral occurrences that I know of in the Paleozoic Rocks of southwestern Ontario. Of course, the rocks do not recognize political boundaries and there are similar, related occurrences in the USA. I’m sure there are other occurrences, not mentioned here, that are not as prolific or well known and I expect there will be new localities in the future. Let’s hope so!
Acknowledgements
hanks very much to Ray McDougall, Margaret Wilson and Reiner Mielke who reviewed this article and offered very useful improvements based on their experiences collecting in southwestern Ontario. Thanks to Don Lapham who provided information about Guelph Dolime quarry, site images and access to his sphalerite specimens from that locality for photography. I appreciate the high-quality faceted stones pictured in the article gifted to me by my brother Brian Joyce, who cut them.
All mineral specimens featured in this article are or were from the collection of David K. Joyce, unless noted otherwise.
References and Further Reading:
Benoit, Gilbert 2012, personal communication
Joyce, David K. www.davidkjoyceminerals.com, “Recent Activities” –several entries
Mielke, Reiner, 2012, personal communication
Sabina, Ann P. 1963, Rock and Mineral Collecting in Canada Ontario and Quebec, Volume II, Misc. Report 8, Geological Survey of Canada, Page 132
Wilson, Margaret 2012, personal communication
www.mindat.org There is detailed info on some of these localities in mindat.org
Wolf, R.R. 1993. An inventory of inactive quarries in the Paleozoic limestone and dolostone strata of Ontario; Ontario Geological Survey, Open File Report 5863,272p.
General
Last November, mindat.org, the awesome internet mineralogical database and forum, plus the Spirifer Geological Society, from Poland, organized a mineralogical conference in Morocco. The conference featured speakers from around the world and was accompanied by extensive field trips, before and after the conference, to classic mineral localities in Morocco. My collecting partner, Ray McDougall and I learned about it a full year earlier, when it was originally promoted. We were two of the first people to sign up! It just seemed like a wonderful opportunity! The registration was sold out a month or so later.
Morocco has been, for many decades, a country that has produced great mineral specimens. Names like Mibladen, Imiter, Bou Azer and many others have become familiar names to people who are interested in well crystallized, beautiful and/or rare minerals. As an admirer of Moroccan silver and proustite from Imiter as well as skutterudite and gersdorffite from Bou Azer, I was keen to have a chance to collect or acquire some of these specimens closer to the source.
The main raison d’etre of the conference and field trips was the study minerals of and the field collecting of mineral specimens. A huge bonus, however, was the social program. The organizers went out of their way to ensure that there were ample opportunities to socialize and learn about Moroccan culture. Every evening there was a large group supper and conversations were lubricated with nice wines and copious quantities of vodka from Poland. Every evening, there were local artists performing Berber music, snake charming or belly dancing. The food was all served group or buffet style and selection was fantastic! Many evenings were spent chatting with mineral lovers from all over the world while listening to great music and nurturing glasses of Krupnik, a Polish honey-dosed vodka.
About Morocco
I’ll just give a brief outline of my observations and impressions about Morocco. I really cannot do it justice from just a two week visit but I’ll let you know what I know!
Morocco is a land of contrasts. The northern coast, where we started our trip is rich with urban life in the cities of Casablanca, Marrakech, Rabat and others on the coast. Just outside of the cities, and all the way to the base of the Atlas mountains are rich agricultural areas that skillfully use the soil and judicious use of water to grow many fruits and vegetables. Morocco is an agricultural country! We observed the most modern of farms, infrastructure and transportation systems to the most primitive, such as people tilling the soil by hand and riding on donkeys.
Closer to the mountains, the image of Morocco changes to one of livestock and tougher forms of subsistence living. Everywhere we went, we saw goatherds and shepherds with their flocks, probably doing things the same way that they have for thousands of years. On the other hand we saw the most modern trucks and cars on the same roads as the people on donkeys. Any piece of arable land in the mountains has a bit of pasture on it or water from a local river diverted to it to grow food.
Once you are over the mountains, the land and climate turns to desert. Not the desert that you think of with sand dunes, but a rocky, barren desert with oases and irrigated farm lands. The Moroccans have become very good at drilling deep wells to obtain water to produce farmland from desert. Everywhere, in the desert, there are people tending flocks of sheep or herds of goats. As well, it is very common to see nomadic people with small herds of camels moving them around an area fairly close to their tents.
The official language of Morocco is Arabic and that is what I heard spoken most often. It seemed that, in the regions where we were, most people speak some measure of French, as well. I’m glad, again , to be able to speak some French and that was always the language of conversation or business during my stay in Morocco. Rarely English.
We saw many modes of dress during our travels. As a general rule, people in the cities were dressed in more modern garb with some people dressed in traditional dress. In the country, it was the other way around with, I think, with a large proportion of people dressed in more traditional clothing.
Marrakech Area
We flew into Casablanca and were picked up by a shuttle arranged for by the conference organizers. We were whisked to Marrakech along a modern highway and before we knew it, we were ensconced in our hotel, a classic oldy, in downtown Marrakech. We were surrounded by mineral loving friends, old and new, excited about the prospects for collecting interesting and unique mineral specimens at a number of classic localities. The first night we were treated to a Moroccan musical group who played folk music and then were joined by a belly dancer, later in the evening. Acquaintances were renewed and many people finally met others that they had read about or had corresponded with.
The hotel was right downtown near the souq and right across the road from the Koutoubia minaret. Every morning at 6:30am or so we were blasted out of bed by an ear splitting call to worship by an imam over the loudspeakers. There was much history around us. The minaret was constructed in 1200AD or so. There were many other buildings that reflected the ancient history of the area.
The transportation method selected by the organizers was a fleet of minibuses that each held 15 or so people. Our bus held all Canadians, plus a driver. Not luxurious but, most of the time comfy. I was, somehow, appointed “fearless leader” of the bus. I preferred “exalted leader” but my crew didn’t seem to want to genuflect to that extent. My job was to try to gather information from the organizers and bring it to the bus or to take concerns and suggestions from the bus to the organizers. We had some fun times on the bus!
Sidi Rahal
The first field trip was to the geode locality at Sid Rahal. The locality is a thick bed of basalt that featured geodes, large and small and collecting was actually fairly easy. Unfortunately the road was washed out due to the torrential rain the day before but some of the buses made it through. These type of busses were not really made for this type of road and some of the drivers were upset at the conditions. Our driver went on strike! So some of us walked in and out of the locality from where our bus was. We only had a couple of hours to collect but even so a number of people came up with respectable finds. The geodes varied greatly and consisted of quartz crystal lined geodes, agate lined geodes or agate filled geodes. Some of the quartz was colourless and some was amethystine. The agates ranged from pure white to banded red fillings, sometimes with drusy quartz interiors. There were lots of Moroccan collectors walking around trying to sell us specimens while we collected, including kids. I purchased a really nice little geode from the little guys pictured below. One of the local geode dealers put up a sumptuous traditional lunch of tea, olives, dates, almonds and breads that we enjoyed thoroughly. After lunch the attendees visited the various geode dealers in the area and, many picked up nice specimens at reasonable prices.
Marrakech is along way from the great mineral collecting localities so we spent a whole day travelling to Ouarzazate. It was a lot of time in a mini bus but we did stop a number of times for “bio breaks”, scenery admiration and many, many mineral stores. There are a LOT of rock shops in Morocco! We headed up over the Atlas Mountains and through the Tizi-n-tichka pass. Here are some of the photos that I took on that journey.
We finally made it to Ouarzazate, checked into the hotel and immediately went to visit the regional Kasbah, a now preserved historic building that was once the seat of power for the regional governor for many centuries. The Kasbah has been well preserved and we had a guided tour that ended at dusk.
After a superb buffet supper (all the meals were super buffets), a good dose of fine wine and vodka, we watched a snake charmer charm his cobra and put scorpions in his mouth, while playing his clarinet-like instrument all the while.
Bou Azer
Next morning, on we went to Bou Azer with visions of great mineral specimens dancing in our heads. There are and have been many mines in the Bou Azer District and we had the opportunity to visit a couple of them. Our bus drew the short straw and made our way about as far as you can go in the Bou Azer District to Ait Ahmane, the famous skutterudite locality. The road to Ait Ahmane was very rough and it was a bone jarring drive. About two thirds of the way there, out bus drivers all went on strike. When we finally arrived at Ait Ahmane, the drivers refused to drive the last few km on the little road to the mine. So we hiked in to the mine and were able to find some massive skutterudite, small, well-formed skutterudite crystals, safflorite crystals as well as what has turned out to be cobaltoan austinite in preliminary analyses. It was a short visit but I was glad to see the place and collect.
After Ait Ahmane we dropped by Agoudal Quarry. There is an underground mine there and a small open cut with dumps that we were allowed to collect in and on. This is the locality that produces nice cobaltoan calcite, sphaerocobaltite and erythrite. A number of people found nice specimens and I was please to come away with a small cavity with bright red, sharp, sphaerocobaltite crystals lining it.
Our travels next took us to Meteorite. It is a small place out in the desert and the hotel could not hold all of the trip participants. We were greeted by another Moroccan folk music band! The hotel set up sort of facsimile Berber tents and beds that were really quite comfortable and Ray and I were happy to sleep in one of those. It had been a long day of collecting and travelling so after supper, most of us just went to bed!
Erg Chebbe Dunes and Taouz
We headed out from Meteorite to a spot that we all would end up enjoying for two nights, the Yasmina Hotel, beside the Erg Chebbe dunes. Really a spectacular spot that gave us a glimpse of the Sahara desert. The hotel is built in a fort-like fashion with all of the buildings inside an enclosure. The pool was fantastic, food very good, and the view of the dunes, spectacular. Each night we were there, we had really good live Moroccan music during and after supper. As usual, Our Polish hosts ensured that there was enough wine to lubricate conversation. It was at Yasmina that I was introduced to Krupnik, the honey laced Polish vodka. Yummm! There was a temporary lake next to the hotel that was, again, a result of the torrential rain that Morocco had received a few days before.
The organizers arranged a fleet of Land Rovers to take us to Taouz! Sometimes they stayed on the road and other times they took off helter skelter across the desert! This locality is a classic vanadinite spot very close to the Algerian border. Taouz was originally a lead mine and some of the workings are still accessible. There are lots of waste rock dumps composed of chunks of oxidized ore consisting of manganese and iron oxides with many cavities containing vanadinite crystals. It was easy to collect there. Again, time was limited but I think that everybody was very happy with the collecting. If only we had more time…
After collecting at Taouz Mine, we headed for a spot near Taouz, where there are ancient rock carvings, and ate our lunch gazing out at the desert, watching grazing camels and the Algerian border.
After lunch, we headed cross-country to get a different view of the Erg Chebbe dunes, enjoying the scenery and the many nomads and their camels that we passed. Pretty darn cool. Back at the Yasmina hotel, we enjoyed a swim to remove the black and brown oxide coatings, another sumptuous feast. One of the highlights of the trip however was the camel ride and then hike up to the higher dunes to watch the sun set. Magic!
From Yasmina we headed for Erfoud to check out the fossil dealers and preparation facilities. I’m not much of a fossil guy but it was pretty neat to see the workers grinding and preparing trilobites. There were some amazing fossils!
From there we headed off to the fluorite locality at Jorf. It was fun trying to collect but I didn’t have much luck. Ray and I tried attacking an in-situ vein but there wasn’t much well crystallized fluorite in it. I did find some sharp crystals on the dumps but most were heavily, iron stained from near-surface workings. The underground workings seemed to be totally abandoned.
Midelt
On to Midelt! This was the site of the mindat.org conference. I won’t go into great detail about the conference but it was very good. Essentially, it consisted of three days of presentations by authors knowledgeable about their subjects. Some talks were about Moroccan minerals and localities while others were international. I presented a talk on “The Cobalt Silver District” right after Georges Favreau from France presented his outline of the Imiter Silver District. Attendees seemed to enjoy both talks and comparing the two great silver localities. Every night that we stayed at The Taddart, there was live music and the usual great buffets accompanied by wine and Krupnik. There were two exceptions, however.
One afternoon, the people of Mibladen put on a mineral and craft show featuring many local dealers and artisans with loads of great specimens to purchase. Of course, bargaining seems to be a part of buying minerals in Morocco and lots of that happened. The people of the area put up a great big Berber tent in the middle of the mineral show and treated us to a very nice lunch. After a few hours of bargaining, buying or just looking, they treated us to a wonderful supper! Afterwards we wobbled back to our minibuses and returned to the Taddart Hotel.
On another night, we left the Taddart Hotel for a “secret” spot which turned out to be an abandoned room and pillar mine near Mibladen for ANOTHER great party. This time the people of the area converted the old mine into a banquet hall. They removed the coarse rocks, spread out gravel to provide a smooth floor and then spread out beautiful carpets, brought in tables, chairs, food and served us a several course meal. Again, wine and Krupnik were involved. There was live music, dancing and much socializing. We were all thrilled.
Mibladen Area
Of course, it would be impossible for us to be several days in the Mibladen/Midelt area without doing some field collecting! The vanadinite and cerussite specimens from that Mibladen are world famous. At one time there were a number of large operating lead mines in the area operated by French companies. There are none operating now but the abandoned workings are constantly being worked by local miners, searching for pockets that contain great crystals. They do find some great ones! They are permitted to collect in the old workings as long as they do not use explosives or power tools.
We first visited the ACF workings which, today, are small independent mines operated by artisanal miners. The vanadinite layers are located about 10m below surface and there are no old workings in them. The miners actually chisel a shaft straight down until they reach the productive layer. This takes about two months! Then they hand chisel the rock until they reach vugs from which they carefully remove the crystals. Hard work! They have small hovels at the top of the shaft that they sleep in if they have discovered something good and don’t want to leave the workings.
Ray and I visited Abdellah at his workings and went down the shaft with him to try our hand at hand chiselling to find a vug. We spent a couple of hours chiseling and only found some small vanadinite crystals. When we came to surface, we each tipped him and purchase some specimens from him.
The other mines that we visited were actually some of the old room and pillar mines. The pillars still have veins of galena, vanadinite, barite, cerussite and wulfenite in them and that is what we worked on. It was pretty amaizing, really. We just walked into one of the portals and worked our way down to areas that looked promising and just chiselled away at pillars and boulders, hoping to break into vugs with crystals. Again, most people that went underground managed to find some sort of good crystals, cerussite and barite being the most popular finds. I did find a nice yellow wulfenite specimen at Les Dalles but, unfortunately, it was lost on the way home, somehow. We worked at both Boulmaden and Les Dalles which were very similar operations.
Aouli and Sidi Ayed
Our last field trip was to Aouli and Sidi Ayed. We had an unusually special old and decrepit car for this final trip on a very cold, windy, rainy day. The car was so special, it had no heat, windows that did not open, no window defogger(a rag to clear the window sufficed), no parking brake(the diver chocked the wheels each stop) and doors with no handles(ropes), not to mention the lack of aesthetic appeal. This probably would not have been too big of a deal on a different day but when we were cold and wet and the windows kept fogging up, it added to the tension of our driver’s insistence that he pass EVERBODY!
Aouli and Sidi Ayed were also mining operations run by French companies but closed in the 70’s and are now totally abandoned except for the brave souls that plumb their depths of mineral specimens. According to our guides, Aouli really has not ever produced much in the way of specmens. Some perhaps but, apparently, most specimens that are labelled Aouli really came from Sidi Ayed. The mine at Aouli was a huge underground mine and I’m glad that we stopped to look around. The buildings that were erected in that steep river valley are amazing. Must have been quite the place in its day! We did not even try to collect specimens at Aouli.
Then on to Sidi Ayed. The road to Sidi Ayed was very rough but our intrepid driver took us right to the end of the road. The end of the road was adjacent to a large open stope and open cuts on a vein that outcropped on surface. There were waste rock dumps on either side of the vein that were loaded with green and blue malachite and azurite. Most of the greens and blues were just fracture coatings but some of the chunks could be broken open to reveal cavities lined with velvety malachite or balls of blue azurite crystals.
The cold winds that blew that day were the forewarning of the snowstorm that was to arrive the next day. Sure enough, overnight, large amounts of snow fell, particularly in the mountains all around us. It was beautiful to look at! The negative effect was that most of the mountain passes were snowed in and impassable for a day or so. As a result people that had flights to catch out of Fez, Casablanca or Marrakech were worried that they might miss them. That resulted in people leaving a day or partially a day early to take the long way around the mountains and avoid the mountain passes. We decided to stay put and enjoy Midelt and the small mineral show of local dealers that was put on at our hotel. We left the next day at our scheduled time, chancing that the mountain pass that we had to traverse would be open by the time we had to cross it. It did work out!
Heading Home
So our seven hour taxi drive from Midelt to Casablanca turned out to be a beautiful drive that started out in cloudy snowy weather and ended up in warm, sunny weather during the drive across a good portion of Morocco. The mountain passes that we had to cross were open and the roads were in great shape. Our driver dropped us off at our hotel in time to catch up on our e-mails before a very nice Moroccan supper. By chance, we ran into two of the key organizers, Tomasz and Agatha in the hotel bar and had a very nice nightcap with them reminiscing the previous two weeks. Nice way to end the trip!
I’d like to acknowledge Jolyon Ralph of mindat.org and Tomasz Praszkier of the Spirifer Geological Society for their tremendous planning, experience, foresight and execution that, along with local partners, provided this unique opportunity to visit an interesting and beautiful part of the world, loaded with great mineral localities.
General During August of 2007, I was privileged to visit the Mary River Project of Baffinland Iron Mines Ltd. (Baffinland), in the Arctic region of Canada, in the middle of Baffin Island. I was working for SNC-Lavalin Engineers and Constructors as Vice president, Business Development, at the time, and we were vying for the contract to be the engineer for the detailed engineering design, procurement and construction management (EPCM) of the iron mine and facilities that Baffinland Iron Mines Ltd. hopes to build there in the future. The Mary River Project is one of the world’s richest and largest undeveloped iron ore projects. The mineralization has a high enough percentage of iron and is free enough from impurities that it could qualify as a direct shipping “lump” ore. This means that a mine could be developed and lump ore shipped directly to customers without expensive and environmentally detrimental processing facilities. This is a big plus for the Mary River Project. On the other hand, the Mary River Project is, climatically speaking, in one of the most hostile places in the world. The ocean around Baffin Island is frozen 9 months of the year, and the average temperature, throughout the year, averages minus 18 degrees Celsius. THAT is cold! Construction of, operation at, and shipping from the mine would be extremely challenging. The ships to move the ore 10 or 11 months per year in these difficult conditions do not yet exist and will have to be constructed especially for this project. A special 120km railway will have to be constructed, on permafrost to move ore from the mine to tidewater. No easy feats! These onerous and difficult requirements are some of the reasons why the Mary River Project has not been developed in the past. The technology and market conditions did not exist to make the operation a reality. Today, technically, those capabilities do exist and Baffinland is working towards making this project a reality. Financially, the project will cost over three billion dollars to build and Baffinland is working towards firming-up the estimated cost of the project and then raising the necessary capital on the world’s financial markets.
The Project
The iron mining complex envisioned by Baffinland Iron Mines is intended to exploit several huge deposits of very rich iron mineralization. The feasibility study recommended developing a large open pit mine at Mary River, a crushing and screening plant, a railway to ship lump iron ore to the Steensby Inlet ship loading facilities. The production rate was envisioned at 18 million tonnes per year of lump iron ore and fines destined for the blast furnaces of Europe and, possibly, the world.
The iron deposits of the Mary River iron deposits are very high grade, consisting, mainly, of hematite and magnetite that require little upgrading outside of a careful mining sequence and are considered direct-shipping ores. That means no upgrading mill or pelletizing plant would be required to prepare the ore for shipping. This fact has simplified the project significantly since there would be less environmental “footprint”. This means that if the ores require no mill to upgrade them, then the physical area of the plant would be reduced plus there would be no chemicals required for treatment of the ores. Best of all, there would be no tailings pond full of ground up waste rock and residual waste chemicals. The project, in some ways is environmentally benign.
It would not be totally benign, however! Baffinland would have to build a large complex to house many hundreds of people, generate power and build and operate a 120km railway to transport ore to Steensby Inlet andto bring supplies back to the mine complex.
One of the biggest challenges of the Mary River Project is that it is in the Arctic! There have been other mines in the Arctic (Nanisivik and Polaris) but most have been underground mines, operations where work is carried out below the surface and away from the VERY severe climate that holds the Arctic in its grasp for much of the year. As well, shipping at these operations was limited to the ice-free times of the year –just a few months. The Mary River Project would have to operate an open pit mine year round, ship ore to the coast by railway, year round AND load it on to gigantic ice-breaking bulk ore carriers that would operate 11 months or so per year! No small order!! It has never been done before.
There are a number of engineering challenges on this project. First, to operate an open-pit mining project year-round in the Arctic is very difficult due to the average minus 50 degree Celsius temperatures during January and February. Second, it is a major engineering feat to build and operate a large-tonnage railway year-round in Arctic conditions AND one that is built on permafrost. Third, year-round shipping through thick ice, such as is required for the Mary River Project, has never been done, in the world, to date. The ice thicknesses are such that several ice breaking ore carrying ships, of a design that does not currently exist, would be required to be purpose-built for this project. This aspect of the project was not part of the scope of that we were considering but is critical for the success of the Mary River project. The ships would probably be designed and built by a shipping contractor.
During August of 2007, I led a team of engineers to Mary River to gain first hand experience of the conditions and the “lay of the land” to put together the best possible EPCM proposal. This short writ-up will give you an idea of what it is like there (in the summer) and give you an idea of what the project is about. It is not a place that many of us have the opportunity to visit!!
Geology
The Mary River deposits are Proterozoic , high-grade, bedded iron deposits interbedded with banded iron formations, iron silicates, greywacke and granite gneiss., granite and hornblende gneiss.
Mineralogy
To date, mineralization has been examined mostly on surface exposures and in diamond drill cores. There has been a 200,000 tonne bulk sample taken to evaluate the potential ore in European blast furnaces. The ore minerals appear to be bedded hematite and magnetite with very little crystallization of interest to mineral collectors seen to-date. In the deeper parts of the deposit, pyrite can be seen in fractures and breccia fillings. As well, certain parts of the deposit have had silica solutions percolating through the mass and breccias can be filled or partially filled with quartz, sometimes with openings of quartz crystals.
The minerals of collector interest that are encountered in the project are minerals related to the metamorphism that the ancient rocks have undergone over time. The local schists are rich in garnets crystals which sometimes are large and very well formed. As well, the schists contain local concentrations of staurolite and anthophyllite in well formed crystals.
No doubt, if and when mining commences, interesting mineral specimens will be uncovered with the many millions of tons of rock and ore that will be moved every year.
Flora and Fauna
I did see some animals during my visit. The Arctic is a very difficult environment but there are a surprising number of animals that reside there.
The animal that many people think about when they think of the Arctic is the Polar Bear. Thankfully, I did not encounter any of these beasts. We were inland most of the time and they usually reside by the sea and on the sea ice. I did see a beautiful Arctic wolf that came up close to the camp. He/she was pure white and came close enough to peer at us from the edge of the camp. I saw lots of snow geese!
Unfortunately, I WAS working so I could not take much time for wildlife photography.
There were also lots of interesting plants. Small wild flowers and even low bush blueberries. I wish that I had time to take more pictures.
Images
Here are a series of images that show some of the sights that I took in on the trip:
This is not a picture of land from 4,000 feet in the air but is a picture of ice floes
in the ocean south of Baffin Island.
Some interesting topography from 20,000 feet in the air!
More ice floes with Baffin Island in the distance.
Interesting polygonal structure of the land, common in permafrost regions.
This is the camp at Mary River that I stayed in. These are the living and office
quarters of the exploration, environmental and engineering people on-site.
A view of Mary River Camp from the tote road from the northern coastal port at
Pond Inlet.
Here is a view of Mary River Camp from the helicopter.
This is Deposit #1 at Mary River. The core of the mountain is solid iron oxide.
See the black at the top? All hematite and magnetite mineralization! The Mary
River camp is at the base of the mountain to the left and back a bit, just off screen.
The air strip at Mary River Camp where freight planes shuttle supplies in from
the coast and helicopters move people around the area and take supplies to the
diamond drill rigs. Deposit #1 in the background.
Here is a view of a diamond drill rig on the side of Deposit #1. What a place
to work!
Some nice Arctic flowers growing in a crack in the lichen covered rock.
Tough existence!
Colleague Martial Cote standing beside the camp inukshuk.
Martial Cote and me at the supply/construction port beside Milne Inlet.
Most of the permanent residents of Baffin Island are Inuit. There no Inuit villages
near the Mary River Project but a large proportion of the employees at Mary
River Project are Inuit.
A geologist working in the “core shack” logging diamond drill core. This is how
the mineralization is outlined and quantified.
When you visit the Arctic, chances are that you will stop at Iqaluit, the largest
town on Baffin Island. All of the signs are in both English and Inuktitut.
All of the buildings are built on stilts to prevent building heat from melting the
permafrost that underlies everything.
Even the houses are built on stilts!
Anthophyllite crystals, 20mm long, in schist
Staurolite crystals in diamond drill core.
The End! I hope that you enjoyed this short view of the Mary River Project and
Baffin Island!
David K. Joyce, Newmarket, Ontario
Dr. Donald V. Doell, Grafton, Ontario
Introduction
In 2016, David K Joyce (DKJ) met up with co-author Dr. Donald V. Doell (DVD) at the annual convention of the Prospectors and Developers Association of Canada (PDAC). The PDAC is a gathering of approximately 28,000 people, mostly geologists, engineers, mining and exploration company executives, investors, and other interested and related people. There are many activities at the PDAC, one of the most interesting being the “Investors’ Exchange”, where people can visit booths of hundreds of mining and exploration companies to learn technical details of their deposits, mineral exploration strategies and/or investment potential.
DVD and DKJ were both there visiting various companies looking at investment potential and, of course, potential for mineral specimen acquisition! There are usually rock/ore or mineral specimens at each booth representing the mineralogy and geology of various deposits. One booth, in particular, was of interest to us. Wallbridge Mining Company (Wallbridge) had operated a small mine north east of Sudbury for platinum-group elements, copper and nickel. During the exploration and subsequent mining stages, Wallbridge had recovered excellent specimens of sperrylite crystals in matrix. Usually, the sperrylite crystals were embedded in chalcopyrite/pyrrhotite matrix but sometimes they were embedded in quartz, associated with epidote. Please see another article on this website, http://www.davidkjoyceminerals.com/pagefiles/articles_brokenhammermine.asp that gives more details about the Broken Hammer Mine, its geology and minerals.
Wallbridge Mining Co. had one particular specimen that had been nicknamed “the Sandwich”, since it appeared to be a rich specimen of chalcopyrite with a layer of large sperrylite crystals in the center( the meat) between outer layers of golden chalcopyrite and rock (the bread). Mine management speculated whether, or not, the sperrylite crystals were not only observable at the front edge of the specimen as a line or were they a discontinuous plane inwards between the layers of chalcopyrite? How to tell without splitting or breaking “the Sandwich”?
DVD thought that it could be possible to “see inside” the specimen, utilizing the advanced x-ray imaging offered by CT Scanners, the type used in hospitals. Of course, CT scanners are usually used for imaging relatively low density internal organs of medical patients. However, we wondered if it would be possible to modify soft-tissue x-ray techniques with a CT Scanner to examine the insides of a much higher density material, a piece of chalcopyrite (density of 4.2 g/cc) that contained sperrylite crystals (density of 10.55 g/cc). It was an interesting discussion and excited our imaginations.
Sperrylite Specimens
A couple of months later, A. Soever, Chairman of Wallbridge Mining, contacted DKJ and asked him if he would prepare and sell some sperrylite crystal specimens on behalf of Wallbridge Mining Co. Subsequently, DKJ took possession of a number of pieces of sperrylite-bearing chalcopyrite. A couple of them were large and had only broken sperrylite crystals exposed on the outside. It occurred to DKJ that it might be a good idea to examine these bigger chunks, internally, using a CT Scanner, as suggested by DVD. He contacted DVD and discussed the matter. DVD, has very good relations with the Montreal Neurological Institute (MNI), at Montreal, Quebec, so he contacted colleagues there and discussed with them, whether such x-ray technique could work on such specimens and was the MNI willing to allow us to try this technique on the Wallbridge specimens. They were agreeable! We contacted Wallbridge and they also agreed to allow us to image ”the Sandwich” to see if sperrylite crystals existed inside the chalcopyrite, in addition to what was observable on the outside.
CT Scanner
The MNI agreed to allow us to use their scanner, a Toshiba Aquilon ONE CT scanner, for a short period of time, when it was not required for medical examinations.
DKJ marked the larger specimens with 1.0cm increments in an attempt to better understand where the sperrylite crystals were later during trimming operations. The idea was to try to orient the fragments in concert with the x-ray images afterwards in an effort to locate any sperrylite crystals as accurately as possible for successful trimming and exposure.
The MNI Technician was made available to us and very quickly adjusted voltages and other parameters to internally image chunks of chalcopyrite. It was agreed to image the pieces in 1mm “slices”, that is, an image of the internal structure of the specimens was captured perpendicular to x,y and z axes every one mm. This allowed us to look inside the specimens, in the same way that you might flip the pages of a book with 1mm thick pages –but in three dimensions! Instantly, we could see that most of the specimens were barren of sperrylite crystals except that every once in a while, a bright white area would appear in an otherwise grey mass - a sperrylite crystal!
As it turned out, the sandwich did NOT have many more sperrylite crystals extending into it in a plane. It looks like a sandwich but, in fact, it is not. There are a couple of buried sperrylite crystals, though, as you can see in the x-ray image of the specimen. DKJ (sadly) returned the Sandwich to Wallbridge Mining Company where you can see it at their office or at select trade shows. It is quite something! If Wallbridge ever DID decide to break it up to better expose the various sperrylite crystals, we totally understand the inner structure and location of every crystal. It would be great challenge to prepare several specimens from it!
Specimen Preparation
Unfortunately, the sperrylite crystals were mostly the kind that are intergrown with the chalcopyrite and rock. As such, most just split irregularly, revealing crystal sections, impregnated with chalcopyrite, rather than separating cleanly as solid crystals do from massive sulphides. One did turn out fairly well. It was a cube modified by octahedral and pyritohedral(?)crystal faces. Despite knowing where the crystals are in the matrix, we are still subject to the vagaries of how the rock and massive will actually fracture. It rarely actually breaks exactly how you expect or want!
So, even though the CT imaging examination worked and we had a good idea where the sperrylite crystals were in these specimens, they were not that many and those that were there were not all that amenable to preparation and exposure. If they were the kind that are solid, discrete from and separated from the chalcopyrite easily, our experiment may have been a more commercially successful.
Acknowledgements and Thank You
We would like to thank the Walbridge Mining Co., particularly Alar Soever, Chairiman and Marz Kord, President, on a couple of counts, particularly for enabling the preservation of sperrylite crystal specimens from the Broken Hammer Mine and for being encouraging about the concept of CT scanner analyses and for allowing us to borrow “the sandwich” for these purposes.
We sincerely appreciate the generosity and cooperation of Dr. D Tampieri and A. Hatem, both of the Montreal Neurological Institute and Hospital, at Montreal.
Thank you to Violet Doell for the great photo’s that she took of us working at the Montreal Neurological Institute.
The Musselwhite Mine
The Musselwhite gold mine has quietly grown into a giant deposit since it first opened in 1997. It is wholly owned by Goldcorp Canada Ltd. and is located in Northwestern Ontario, 480 km NNW of Thunder Bay. The mine currently produces ~260,000 ounces of gold per year and has produced 3.1 million ounces to date with a current mine life extending to 2019 and considerable potential for further discoveries. Access to the ore zones is via a portal and ramp system which now extends down to the 945 metre level.
Gold was first discovered in the area in 1962 by brothers Harold and Allan Musselwhite of Kenpat Mines Ltd. who found erratic gold mineralization in a quartz vein on the north side of Opapimiskan Lake and several showings in iron formation on the south side of the lake. These two determined prospectors continued to explore the area largely on their own until 1973 when a syndicate of Dome Exploration, Canadian Nickel Co., Esso Minerals Canada Ltd. and Lacana Mining Corp. stepped in to finance further work. Years of exploration drilling eventually led to the discovery of the West Anticline Zone in 1983 and the T-Antiform Zone in 1986 and outlined 1.8 million ounces of gold. The remaining partners in the syndicate at that time, Placer Dome and TVX, had faith that much more ore would be found once they were underground and proceeded with development of the Musselwhite Mine.
The mine opened in 1997 and over the following years several major ore zones were found on the lower limbs of the PQ Deeps synform adjacent to the original T-Antiform ore zones. The remaining reserves and resources (Indicated + Measured) sits at 2.3 million ounces, with a further 0.85 million ounces of inferred resources. Combined with the past production, these resources give a grand total of 6.2 million ounces, qualifying Musselwhite as "giant" deposit" and more than justifying the developer's faith in this deposit.
GEOLOGY
Musselwhite is found within the northwestern portion of the Archean age Superior geological province and lies along the edge of the North Caribou proto-continental core, at the boundary with the Island Lake Domain. The host rocks are about 2.98 billion years old and the age of the ore at Musselwhite has been determined to be 2.69 billion years. Mineralisation is currently believed to be related to an orogeny (mountain-building event) caused by the collision of the Oxford-Stull Terrane about 75 km away, much like the collision of the Indian sub-continent with Asia.
Musselwhite is somewhat unusual in that the host rocks are well within the high temperature and pressure amphibolite grade metamorphic area (formed at ~550 deg C and 9 km depth), more than 5 km from the lower temperature and pressure greenschist grade rocks. The predominant ore host is a silicate facies (variety) of a banded iron formation composed of coarse almandine garnets in fine-grained grunerite (iron-rich amphibole). During shearing the grunerite flowed in a ductile manner while the garnets proved more resistant and prone to fracturing. Mineralised shear zones within this unit are characterised by quartz flooding and veining, coarse hydrothermal garnets, green hornblende replacing the grunerite, and pyrrhotite as veins and blebs. Gold is directly proportional to the pyrrhotite content and the great majority occurs with pyrrhotite filling fractures in the garnets. Smaller ore zones are also found in the adjacent chert-magnetite oxide facies of the iron formation and rare gold-quartz veins are also found scattered throughout the overlying basaltic volcanic rocks. The majority of specimen-quality samples come from these scattered quartz veins in the volcanic rocks or secondary, remobilised veins in the chert-magnetite iron formation.
The Campbell Red Lake Mine
The Campbell Mine is one of the great gold mines of the world, having produced well over 11.15 million troy ounces of gold, so far, in its life-time, up until the end of 2005. In recent years, the Campbell Red Lake Mine has produced gold at a rate of roughly 200,000 troy ounces per year and shows no signs of letting up!
The claims that contain the Campbell Mine were originally staked in the original Red Lake gold rush in 1926 but were re-staked several times before the mine eventually went into production during 1949. The current claims were staked by Colin and George Campbell, cousins, and their partner A.K. McLeod. George was an experienced prospector who had worked for the Timmins brothers in the Porcupine gold camp. His brother Frank had been on the prospecting party that discovered the Dome Mine. George had lived in Red Lake since the early 1930’s prospecting, staking and selling claims. A tough living!
The partners were conducting reconnaissance on some claims that had reverted to Crown land and found some old diamond drill core. They had it assayed and the results were good enough that they immediately re-staked the claims! They conducted trenching and eventually found enough showings to enlist the help of promoters on Bay Street, in Toronto, to develop a mine on the property. The promoter that got the property financed, initially, was none other than Arthur White, who, eventually, became controlling shareholder in Dickinson Mines. Goldcorp Inc.’s Red Lake Mine was for many years run by Dickenson Mines and, prior to the discovery of the High Grade Zone, was called the Arthur White Mine.
Arthur White set up Campbell Red Lake Mines with a capitalization of 3.5 million shares valued at one dollar per share. Dome Mines, one of the pre-curser companies of Placer Dome Inc. sent a team of people from their Sigma Mine in Val D’Or to evaluate this new property and eventually purchased a controlling interest. The mine was a key producer in the Dome Mines fold for many years, and then Placer Dome. Early in 2006, Barrick Gold Corp. took over Placer Dome (to be come the largest gold mining company in the world) but sold all of Placer Dome’s central Canadian properties, including the Dome Mine and other Porcupine area properties (Timmins Joint Venture with Kinross Gold), Musselwhite Mine and the Campbell Red Lake Mine, to Goldcorp Inc. The Campbell Red Lake Mine and Goldcorp Inc.’s Red Lake Mine are being merged to form one efficient, excellent mining/milling complex. The two operations are both staffed with very experienced professionals staff and workers and the combined operation will be producing gold for many years to come!
The Whopper
In 1979, extremely high-grade gold was encountered in 1221 West A Stope in the F-Zone of the Campbell Mine at about 1600 feet below surface. The ore was largely composed of very rich leaves and clots of gold in the quartz carbonate vein material in altered basalt. There was so much gold in the rock that it only partially fractured with explosives and much of it had to be pried off of the face with scaling bars! Although most of the high grade went into the mill, a number of extremely rich pieces were recovered and kept in the vault. Most of them found their way to the mill over the years but one, “The Whopper” was retained until recently.
The Whopper was examined by the mill metallurgy department who estimated that there were 431 troy ounces of gold in the chunk. THAT is high grade! Recently, the Whopper was broken up and a number of samples on David K. Joyce’s website are from that amazing piece, from the 1221 West A Stope.
Note the 1.25” diameter blasthole remnant that runs across the middle of the Whopper! That was full of explosives at one time but the rock is so held together with gold, it would not break any finer. The different colour in the two photos is due to different light sources when the images were taken.
Giancola, D. 2004. The Canadian and American Mines Handbook, Toronto, Business Information Group, Ontario
Kutz, K.J. 1998. Untold wealth, Canada’s mineral heritage, Darien, Gold Fever Publishing, CT
Misiura, J. 2006 Goldcorp Inc., Personal communication
Smith, P. 1986. Harvest from the Rock, Toronto, MacMillan of Canada, Ontario
About the Red Lake Mine and Specimen Recovery
General
The Red Lake Mine, owned by Goldcorp Inc., of Toronto, Ontario, Canada, is, currently, the highest grade gold mine in the world. The mine has operated since the 1940’s but little is left of the old orebodies. All current mining is accomplished in the “High Grade Zone”, discovered in 1995. The mining operations produce about 600 tons per day at a mill-head grade of, currently, well over 2.0 ounces per ton. The High Grade Zone(Nov., 2002) consists of 1.85 million tons (proven and probable) of ore grading 2.05 troy ounces per ton. At current mining rates, there is enough ore to sustain the mill for over 10 years at the current mining/milling rates. In 2001, 503,385 troy ounces of gold were recovered at the Red Lake Mine!
Goldcorp Inc. has taken the unusually progressive step of preserving native gold specimens. It would be easy for Goldcorp Inc. to simply mill all of the gold ore in the mine, pour it into gold bars and sell it as gold bullion. Instead, Goldcorp Inc. realized that gold specimens are rare in nature. They are natural, beautiful sculptures of a relatively rare mineral. Gold is a special mineral in that, like few others, it has a high intrinsic value, in addition to its value as a mineral specimen. A gold specimen is a very worthwhile keepsake that is a timeless legacy of nature at work in forming the Red Lake Mine orebody.
The Geology of the Red Lake Mine
The Red Lake mine is located in the Red Lake greenstone belt that consists of a typical Archean sequence of metavolcanic and metasedimentary rocks.
Gold occurs in the Balmer assemblage (2992-2958 my) which occupies the core of the above sequence. The gold deposits of Red Lake area are an example of the 'Archean Load Gold' model. Goldcorp geologists believe that gold bearing hydrothermal solutions percolating through fracture systems in altered volcanic rocks were “trapped” by intrusions of ultramafic rocks that acted as dams, thus concentrating the gold bearing solutions. These hydrothermal solutions eventually solidified into the gold bearing mineralization that we now see in place in the High Grade Zone at the Red Lake Mine.
The Mineralogy of the High Grade Zone
In general, the gold mineralization at the Red Lake Mine is present as native gold that is often visible. On occasion, extremely high grade zones are encountered where localized grades of the ore run in the thousands of ounces per ton. This is where the gold specimens are found. Those zones are an awesome sight to behold!!
Native gold abounds as thick, dense clots, rich zones of particles and as coarse plates and leaves. The platey and leaf-like habits of gold provide the best mineral specimens since the leaves and plates protrude from the rock matrix in aesthetically pleasing combinations.
The gold is really the only mineral that occurs in museum/collector quality specimens, often associated with pyrrhotite and pyrite. There are occasional zones rich with massive stibnite, berthierite, chalcopyrite, sphalerite, arsenopyrite, magnetite and other common metallic minerals impregnated with native gold that make handsome and interesting specimens but there really are no excellent specimens of these species. Having said that, there have been numerous very rare species noted in polished section work aimed at understanding the mineralization better. A list of the possible other minerals determined mostly by chemistry, only include: electrum, boulangerite, zoubekite, hessite, tetrahedrite, benleonardite, ullmanite, pentlandite, gersdorffite, gudmundite, aurostibite, bournonite, lollingite, etc. Perhaps we’ll find some of the rarer ones in large or crystallized specimens some time!!?
The non-metallic “gangue” minerals are usually composed of white,grey or black quartz, tourmaline, mica, carbonate(iron-rich), sericite and the minerals that compose the altered volcanics, one of the more common rocks hosting the gold mineralization.
Specimen Recovery
Specimen recovery is largely accomplished by mine “beat” geologists and the miners who work on their beats. Each geologist at the mine has a section of the mine that is his or her “beat” that they are responsible for. They travel their mine beat regularly, noting geology, mapping, marking up the ore zones for the miners and taking samples to determine and monitor the grades in each stope or working place.
When geologists or miners detect very high grade ore, ie., massive or very obvious leafy gold in the ore, they isolate some of the material for movement to surface. This specimen-potential ore is placed in locked aluminum boxes, usually in sample bags that record the location in the mine where the samples
originated.
The boxes are then moved to the main levels by miners and taken up the shaft in the cage. The locked boxes are moved to safe storage, on surface and eventually to the vault for processing.
Specimen Preparation
Periodically, David K. Joyce visits the mine and works under the constantly watchful eyes of the mine security guards to break open the large rough pieces of gold bearing rock to better expose the gold.
His experience with gold and other minerals over 19 or so years in the business and for 35 years as a private collector have enabled him to understand the aesthetics and the associations of gold as mineral specimens that make them interesting and beautiful. He uses mechanical breakers, hammers and chisels to crack and pry away barren rock, in order to expose the relatively rare and beautiful leafy or coarse gold to best effect. Most of the gold specimens are prepared in this way.
In some specimens, the gold remains obscured by stubborn quartz or carbonates and these warrant further treatment. They are immersed in either hydrochloric or hydrofluoric acid in the mill laboratory facilities. These sorts of specimens are the minority, however.
The hydrochloric acid is used to remove the carbonates from a specimen. The hydrofluoric acid is used to leach away solid quartz and some other minerals. Sometimes, parts of a specimen are “masked” with a protective covering to keep the acid away from important parts of the specimen. That way, just part of the specimen is selectively etched while leaving the rest of the specimen in its natural “as found” state. This technique can expose the beautiful gold nicely while preserving the informative mineralogy/geology of the rest of the specimen.
Gold Content Determination
Each specimen is evaluated to determine its gold content. These measurements are necessary to determine the gold content to ensure that each specimen is not sold at a price less than the intrinsic value of the gold that it contains. The specimens that can be sold at a premium price over their gold content value are offered for sale to collectors, museums and other institutions. If the specimen cannot be sold at a premium over gold content, then it is reworked so that it can be sold or is simply sent to the mill so that the gold can be recovered from it. It takes a considerable effort to recover specimen grade ore, process it, measure it and sell it , so a premium is an absolute necessity to ensure that the specimen enterprise is viable.
The gold determination is accomplished using the age old “Archimedes principle” of determining the density of the specimen by weighing in air and water and then comparing the relative weights to the volume of water that it displaces. Combined with a factor considering the density of the gangue mineral and the well known density of gold itself (19.2 times the density of water!!), this is an accurate method of determining the actual gold content of a specimen.
Sales of Gold Specimens
Specimens are offered for sale on David K. Joyce’s website which can be accessed directly at www.davidkjoyceminerals.com or through a link from Goldcorp Inc.’s fantastic website at www.goldcorp.com. As well, Specimens are sold at a limited number of shows such as the Denver and Tucson Gem and Mineral shows. Hundreds of specimens, each unique, have found their way into institutional and private collections around the world over the past couple of years.
General
Here are some views of the Red Lake Mine to help you visualize this magnificent new mine.
By David K. Joyce and Raymond McDougall
The land around Gibson Road East, near Tory Hill, Ontario abounds with calcite vein-dykes and the minerals that we often associate with calcite vein-dykes, particularly fluorapatite, titanite, amphiboles, microcline and phlogopite. Every Fall, I look forward to collecting with my mineral friends Ray McDougall, George Thompson and Terry Collett in the woods on Gibson Road East, in a quest to find nice crystals and perhaps top what I/we found last year. This year, 2019, turned out to be an exceptional year! The weather was perfect fall time –warm to cool, no rain, sunny, Fall colours in the hardwood forest, no mosquitoes or black flies AND we did find nice minerals in an exceptional, unique calcite vein-dyke.
Figure 1) A pleasant Fall scene on Bay Lake, on the road to Ray’s Home
Figure 2) Fall colours were great this year in the Bancroft area!
About “Calcite Vein-Dykes”
Over thousands of years since the end of the last ice age, weak, circulating, slightly acidic, ground water from the soils over and around the calcite deposits, slowly dissolve the calcite away, exposing the crystals on the wall rock-contact and freeing crystals that were suspended in the calcite. Typically, vein-dykes are dissolved to a depth of a couple of inches to 12 or more feet, although a few feet is more normal. The depressions that are left by the dissolved calcite have been filled in over the millennia by silt, dirt, glacial till and leaves and roots. We have to dig down through all of that to get to the crystals! The process starts with scraping leaves away from a likely looking spot, hacking through roots and dirt, lifting out glacial till and country rock that has sloughed into the depression and, eventually, reaching crystals on the wall rock and loose crystals that are down in the soil just above the remaining calcite. It is hard work and we never know what we’ll find as we dig along strike.
Calcite vein-dykes are a unique type of deposit that we find in the Metasedimentary Belt of the Grenville Geological Province. They are a hybrid type of deposit with characteristics similar to both veins and dykes. Generally, they are “vein-dykes”, mostly composed of coarsely crystallized calcite with fluorapatite and phlogopite and sometimes other mineral crystals suspended in them. A key theory of calcite vein-dyke formation is that heat produced by intruding igneous plutons, perhaps aided by fluxing agents, drew carbonate out of sedimentary rocks, as a melt, in proximity to the plutons. The hot carbonate melt was mobilized and forced into openings in surrounding rocks. Some people believe that some of the bigger calcite vein-dykes are more closely akin to carbonatites. Regardless of origin, as mineral collectors, we like the fact that the mobile calcite caused re-crystallization of the rocks that it contacted. The contacts between calcite vein-dykes are characterized by large crystals of minerals that reflect the composition of the surrounding rocks. So, in feldspar/mica/amphibole-rich zones of country-rock, the crystals that form at the contact between the calcite vein-dykes and the country rock are usually large feldspar/mica and amphibole crystals. If there is significant titanite in the surrounding rocks, then relatively large titanite crystals are usually found on or with the feldspar crystals. The calcite vein-dykes in the Gibson Road East area cut through feldspar-mica-amphibole schists and gneisses so those are the main kinds of crystals that we find. In addition to those minerals fluorapatite which seems to come with the calcite, not from the surrounding rocks is found throughout the calcite and attached to the walls of the vein-dyke country rock contact.
Back to Collecting!
We assembled near Bancroft at Ray’s beautiful home in the woods in late September, 2019. George is a farmer and, unfortunately, the timing in both such collecting projects in both 2019 and 2018 has been such that he was only able to join the rest of us for a small part of the time while we were collecting. The reason was that it was harvest time and he had to spend much of that time, at the farm harvesting and storing his corn crop.
We decided to collect in a promising vein-dyke we had come to refer to as “Titanium City” because of the large amounts of small titanite crystals that we had found there in two previous years. In the earlier years, we had located the vein dyke and started excavating through the roots, leaves, dirt and boulders along strike. Some nice, small titanite crystals had been found and it certainly was a titanium-rich system! The excavation along strike had taken us to 3-4 feet in depth before the un-dissolved calcite was encountered.
Thankfully, George was able to join us for a full day at the beginning of our week. The earlier collecting had taken us down to the undissolved calcite, and along strike to a spot that was clogged with large boulders of sloughed country rock. The hole seemed to go down under the boulders. George was able to break the boulders into sizes small enough to manhandle them out of the hole, so that we could dig downwards. George and Terry took care of this job handily. They were the brawn of this project. Those two guys seem impossibly strong and Ray and I usually watch them execute feats of strength and endurance in awe. I’d like to say that Ray and I are the “brains” behind the brawn but it’s just not true. All of us have a pretty good head for collecting techniques, planning and carrying out projects. So the boulder chunks were moved out of the way so digging downwards could continue. George “opened the door” to our successful collecting and adventure.
Figure 5) Ray starting to dig “the tunnel”
Figure 6) Terry at the entrance to the tunnel
As we dug down in the hole under the now-gone, decimated boulders, we found that the calcite “floor” of the trench was not the true floor. There seemed to be a hollow filled with debris under the calcite, which turned out to be a mere calcite “shelf”. As it turns out, it was a substantial hollow that a person could climb into as excavation progressed. And progress it did! For two days we dug laterally under the calcite ledge, propelled on by the scent of moist dirt, organic material and the promise of well-formed mineral crystals. As we dug, we used buckets or bins to move the debris to the entrance, of what became a “tunnel”, to be lifted out, dumped and sifted through for crystals.
Terry is from Nova Scotia where the mineral collecting is very rewarding but very different. Most of the collecting that Terry does out east is by chiselling crystals out of vugs and veins in cliff faces and rock outcrops around the Bay of Fundy. This type of collecting is very different with different minerals and Terry gets a kick out of it! In addition, he is a great cook and lunch-maker!
As we dug under the calcite, we were careful to not damage the wallrock of the vein-dyke on our right. It was covered with crystals of fluorapatite, phlogopite, amphibole and some titanite crystals. We’d dig out a few feet and then chisel or pry crystals off of the wall. Really, though, most of the crystals on the wall were damaged by frost since being liberated from the calcite thousands of years ago. There were some good ones though!
Figure 7) Terry happily collecting crystals off of the wall
Figure 8) Ray in the tunnel. Note the crystallized wall on the right
As we removed the debris from the tunnel, the height of it in the tunnel decreased somewhat so that eventually we could see over the top of it. By this point, Terry had named the tunnel the Crystal Palace Stope. For most of the time, it just looked like more tunnel but when we got 6 metres or so back, it was apparent that there was a large opening at the end. A cave! Lots of room for a man to crawl in, sit up and relax, then turn around and shimmy back out. The cave was interesting in that above was calcite, while on both sides, was wall rock. The wall on the right side was covered with crystals, just as the tunnel had been. There were smaller shelves of calcite attached to the walls that seemed to indicated past water levels and calcite dissolution. When sitting in the cave, looking back towards the entrance of the tunnel and then looked down, There is a pristine pool of water about four or five feet down. It is hard to see in the photo, since the water is so clear but it is there. There were no traces of animal activity in the cave but We did notice a couple of spiders and so imagine there must be some small entrance into the cave from surface.
Figure 9) David, underground, collecting crystals off of the vein-dyke wall. R. McDougall photo
Figure 10) Terry is very good at chiselling!
Figure 11) Looks like these are Terry’s legs!
Figure 12) Mostly fluorapatite crystals on the wall and ceiling of the vein-dyke
Figure 13) David sitting in the cave looking down 1.5m at a pristine water table pool
Figure 14) The left side and back of the cave showing partial calcite shelves
There were very few good crystals suspended in the debris. Most of the good ones were chiseled off of the wall of the vein dyke. We wrapped all of the specimens in grocery bags or newspaper and packed them for the trip back to Ray’s place for preliminary cleaning in his facilities.
Cleaning has been fairly simple. The titanites, apatites and amphiboles responded nicely to a quick dip in Super Iron Out, which seemed to dissolve the thin coating of iron oxide. A quick tooth-brushing removed most of the organic material and any light silica or sulphate coating. I tried putting the feldspars in iron out but found that some looked less attractive after even a brief soaking. I elected to just lightly mechanically clean them and leave the natural patina alone. Similarly, the phlogopite specimens needed just a light brushing and possibly a quick iron out dip to brighten them up. Ray air abraded all of his specimens which removed the last lustre-inhibiting agents and this proved to be an excellent technique for finishing them.
Here are some pictures of some of the mineral specimens that we found.
Figure 15) Dave’s favourite fluoro-richterite cluster before cleaning
Figure 16) Same fluoro-richterite specimen after cleaning. Odd bladed habit!
Figure 17) Bladed fluoro-richterite crystal cluster, 7.0cm tall. R. McDougall Photo
Figure 18) Fluoro-richterite crystal cluster, 6.0cm tall. R. McDougall Photo
Figure 19) A 1.3cm Titanite crystal on microcline crystal matrix
Figure 20) A parallel-growth titanite crystal on microcline, specimen 11.0cm tall
Figure 21) A sharper, 7.0cm fluorapatite crystal on a corroded crystal
Figure 22) Here is the nicest, larger (18.0cm long) fluorapatite crystal that we collected this year
Figure 23) Titanite, 4.0x3.0x3.0cm
Figure 24) Doubly-terminated fluorapatite crystal, 9.0cm tall. R. McDougall Photo
Figure 25) Singlely-terminated fluorapatite crystal 10.0cm tall, R. McDougall Photo
Figure 26) Back of one of the sharper phlogopite crystals on matrix
Figure 27) Front of the same doubly terminated crystal, seemingly hemimorphic
Figure 28) Phlogopite, 6.0x5.0x4.0cm
Rudy’s Feldspar Mine.
Ray took Rudy for a walk one morning to wear off some of Rudy’s “young dog energy”. Somehow, he found a promising microcline spot up on the side of a hill, west of where the underground workings were. He brought back a couple of promising looking crystals, so a day or two later, Ray and Dave went off with Rudy to find that spot again and try to extract some specimens. The occurrence was protruding out of the hillside as a little cliff and we started prying off large chunks of rock to better expose the seams. We did manage to expose some good looking zones of crystals and harvested some very good samples.
Figure 29) WAY back in on Gibson Road, on the way to Rudy’s Mine, Rudy leading
Figure 30) Rudy’s Mine with Ray in it!
Figure 31) Microcline cluster, 15.0cm across, from Rudy’s Mine
Figure 32) The twinned, 6.0cm crystal of microcline
Figure 33) Another picture of the Rudy’s Feldspar Mine occurrence
Figure 34) Microcline cluster from Rudy’s Mine, 10.0cm across
Figure 35) Twinned Baveno-law microcline crystal, 3.1cm across . R. McDougall Photo
Figure 36) Superb cluster of Microcline crystals with calcite, 12.0cm across. R. McDougall Photo
Gibson Road East, 2018 and 2017
We also had great collecting experiences in 2018 and 2017! The same crew, George, Terry, Ray and David. We worked on different vein-dykes, though, and some yielded some good specimens.. Each was labelled with handles such as “The Big Hole”, another was “Titanite Tree” and yet another was “The Zone of Goodness”. “Charles’ Hole” and “Ray’s Hole” also yielded some good specimens.
“Titanite Tree” was a vein-dyke exposed after a strong wind storm that knocked down several large maple trees and in the roots were…titanite crystals!! We dug in that vein dyke and ultimately liberated some nice titanite and fluorapatite crystals.
The “Zone of Goodness” was a very small seam, probably not really a full-fledged vein-dyke, that yielded very nice, high-quality, if relatively small, amphibole and microcline crystals in a tight seam. George did the majority of work on that one and utilizing David’s Pionjar drill, liberated some nice plates of those minerals with feathers and wedges.
“The Big Hole” is still a work in progress. It is the deepest weathered vein-dyke encountered, to date, out on Gibson Road East. A couple of very high quality titanite specimens, one a beautifully twinned crystal have been recovered from the Big Hole but, considering the hundreds of five-gallon pails of debris that have been removed from that hole, the specimen recovery has been disappointing. The best is yet to come!(someday…)
Figure 37) David K. J. “diggin’ in a hole!”. R. McDougall Photo
Figure 38) Ray loosening up the dirt and roots at the top with his mattock
Figure 39) Terry supervising Ray’s digging efforts
Figure 40) Amphibole crystals, right out of the dirt!
Figure 41) Sharp, twinned amphibole crystal
Figure 42) Fluorapatite, naturally weathered out of the calcite
Figure 43) Amphibole, 10.0x8.5cm, “Zone of Goodness”
Figure 44) Amphibole, 6.5x4.6cm, “Zone of Goodness”
Figure 45) “Titanite Tree” location
Figure 46) Terry Digging for titanites at the Titanite Tree spot
Figure 47) Ray (L) and George (R) Drawing cards to decide pick order. Terry looks on
Figure 48) Titanite crystals from the Titanite Tree location
Figure 49) George working the car springs and chisel at the “Zone of Goodness”
Figure 50) George in the “Zone of Goodness”
Figure 51) Terry standing in “The Big Hole”
Figure 52) Carolyn, Ray’s better half, came to see where Ray was getting so dirty!
Figure 53) How we mucked out the Big Hole
Figure 54) The Crew, left to right: David K. Joyce, Terry Collett, George Thompson, and Ray McDougall
Many of the properties in this area are private. Others are subject to claims or other rights. All collecting at such sites may only be undertaken with the permission of the owner of the applicable property rights.
This post does not constitute advice or recommendation to travel to the localities mentioned, and any decision to do so is each person’s own risk and responsibility. Adherence to applicable law and respect of private property are fundamental, and each of us is individually responsible – for ourselves, families and friends, and to the mineral collecting community as a whole – to be compliant and respectful at all times. If you are crossing or conducting any activity on private property, appropriate permissions must be obtained.
The Engineer Mine has been an intriguing source of gold for over a century. Born as an offshoot of the Klondike gold rush, the Engineer Mine was originally developed as a remote underground gold mining operation, and then, eventually, complete with a fully serviced town. Since those early, heady days, a number of companies have examined the property, all hoping to find the geological key unlocking the larger gold resource that may lie within or near the current workings. Currently, the six crown grants claim and six surrounding claims are controlled 100% by BCGold Corp (BCGold). BCGold has been involved with the property since 2007.
BCGold is a Vancouver based, TSX-listed company with a fully diluted market capitalization of $5M (2012), focused on exploration and development of copper and gold deposits in “first-world” political environments, particularly British Columbia and the Yukon. It has a number of projects in various stages of development. BCGold’s main focus, at the present time, is advancement of the Engineer Mine property.
BCGold has been conducting both regional exploration and Engineer Mine-focussed exploration and resource development, in the area for the last five years. In 2012, surface exploration consisted of mapping plus soil sampling to follow up on geophysical anomalies to correlate geochemical anomalies. Underground sampling to-date has confirmed the potential for development of a resource that could sustain a modest mining-milling operation. There is a mill on-site capable of processing 30tpd of ore per day to produce a gravity concentrate on a seasonal, campaign basis. The mill consists of a crusher, ball mill, screen deck and Dieter shaker tables. That mill could be de-bottlenecked fairly easily to accommodate a larger throughput. As well, BCGold has been conducting regional exploration around the Engineer Mine in the belief that a lower grade but higher tonnage resource may exist that could potentially support a large tonnage mining/milling operation.
I met senior management of BCGold Corp at the Prospectors and Developers Association of Canada Annual Convention (PDAC) in Toronto and they were keen to explore the mineral specimen producing potential of the property. Our discussions led to an agreement where I would spend a week or so at the mine during the 2012 summer exploration season and work alongside mining and geological crews in an effort to recover specimens from active and historically producing zones and dumps of the mine. Specimens that have been recovered will be offered to shareholders, collectors, museums, etc., and serve as a legacy of a unique and geologically interesting gold mine. To view Engineer Mine mineral specimens for sale on this website, please click here.
BCGold’s goal for the 2012 summer exploration season was to dewater Levels 6 and 7, rehabilitate the winze needed to access them from Level 5 down, rehabilitate the two levels and then conduct a complete sampling program on the veins exposed on those levels. Mining crews from Ampex Mining Ltd. were retained to carry out the work. I travelled to the site in August of 2012 with Darren O’Brien, BCGold’s Vice President of Exploration.
The Engineer Mine is located on the eastern shore of Taku Arm, part of Tagish Lake, in northern British Columbia (BC) near BC’s borders with the Yukon Territory (Yukon) and Alaska. It is in the Atlin Mining District of British Columbia about 32km west of Atlin. Transport in and out of the mine site is usually through Atlin, BC and Carcross, Yukon, by air, barge or ice road.
The following section on Geology has been largely extracted from BCGold documents, verbatim.
Quartz veining and gold mineralization occurs in two modes at the Engineer Mine property, in brittle deformation and hydrothermal breccia zones along Shear Zone “A” and along structures outside of the Shear Zone “A” deformation zone.
Shear Zone "A"
Shear Zone “A” is a northwest-trending 200 metre-wide shear zone with a protracted deformation history, related as a splay to the major terrane-bounding Llewellyn fault. Earliest semi-ductile deformation along Shear Zone “A” may be as old as Late Triassic. Shear Zone “A” was reactivated along its northern boundary in the Eocene. The reactivation coincides with the emplacement of a volcanic complex immediately to the southeast at Engineer Mountain; part of the Sloko Group. Hydrothermal fluids related to the Sloko Group volcanic complex were focused along Shear Zone “A” and other pre-existing fractures on the property, resulting in gold-bearing hydrothermal veins and breccias.
Brittle Deformation and Hydrothermal Breccia Zones
The first mode of gold mineralization at the Engineer Mine property, occurring in brittle deformation and hydrothermal breccias zones along the Shear Zone “A” deformation zone, represents a bulk tonnage gold target. This gold occurs in quartz-calcite-pyrite cemented hydrothermal breccias and quartz vein zones up to 50 metres wide and along a strike length of more than 400 metres. The breccia zone remains open along strike and to depth and require further drill testing.
Several breccia types are recognized in core, including pyrite cemented polymict breccias, fine pale quartz-cemented breccias, dark siliceous breccias with varying clast content, and intrusive clast breccias. Overprinting, multi-stage quartz-pyrite veining relationships are also recorded in core. Gold values are highest in zones of fine quartz flooding, and high silver values are attributed to quartz-arsenopyrite-stibnite veins. BCGold Corp is conducting geochemical and other prospecting techniques in an effort to identify potential bulk tonnage gold targets. Many other gold exploration and mining companies (Goldcorp Inc., Detour Lake Gold, Osisko Mining Corp., etc.) have been successful with this strategy. ie exploring for bulk tonnage gold deposits around former producing, smaller, high grade deposits.
The mode of mineralization of most interest for mineral specimens at the Engineer Mine property is in high-grade gold and silver veins that occur outside of the Shear Zone “A” deformation zone. These quartz-calcite veins formed in pre-existing structures that were re-opened during the Eocene hydrothermal event and reactivation of Shear Zone “A”. To the south of Shear Zone “A”, the veins are both extensional and shear in character. They show a structural relationship to Shear Zone “A” movement. Historic production in the area was from the Engineer and Double Decker veins (view Summary Map) that extend south from the reactivated section of Shear Zone “A”. These veins are less than 2 metres wide, strike northeast, and pinch and swell along strike but have good vertical continuity.
High Grade Veins
Other important gold veins that occur outside of the Shear Zone “A” deformation zone are the high-grade Shaft vein and the Boulder-Governor vein system; all are to the north of Shear Zone “A”. The Shaft vein is vertical on surface but changes to moderately southwest-dipping at depth. It produces coarse free gold. A high-grade zone on the Shaft vein, 113 metres below surface on the 5 Level underground, has bands of arsenopyrite (and stibnite?) up to 1 centimetre wide. The mineralogy is similar to the very high grade Engineer vein to the south. The nearby Boulder-Governor vein system produces free gold in quartz and carbonate concentrated in hydrothermal breccia zones up to 5 metres wide and 50 metres long at vein intersections. The veins strike northwest and southeast. Bonanza gold grades were mined in the 1990’s at these vein intersections.
Host Rocks
The host rock to all the veins and breccia zones on the Engineer Mine property is argillite and greywacke of the Laberge Group. Monzodiorite dykes related to the Sloko Group complex occur across the property, displaying varying degrees of quartz-carbonate-clay alteration. Some of the most altered dykes may be rhyolite dykes from the same intrusive event.
The history of the Engineer Mine property dates back to 1899 when a couple of Swedish prospectors located a yellow metal on the shores of Tagish Lake. C.A. Anderson, an engineer from the Yukon & White Pass Railway followed up on the Swedes’ information and discovered visible gold in quartz/calcite veins on the shore of Tagish Lake, below Engineer Mountain. He returned with associates, in July, 1899, and staked the Engineer group of claims (Mauthner et al, 1996). After a small amount of development work, the Engineer Mining Company allowed the claims to lapse in 1906.
The early history of the Engineer Mine is closely associated with Captain James Alexander who, by all accounts, was an interesting character. James Alexander immigrated to Canada, from England, in 1899, drawn by the romantic wilderness life of British Columbia. For a year or so he sailed the coast of British Columbia doing various work and was, apparently, particularly interested in minerals. Alexander took a break from pioneer life in 1900 and travelled to England and then South Africa to fight for England in the Boer War. He attained the rank of Captain in the Third Dragoon Guards and, after the war, returned to British Columbia (Brook). He was on the survey crew that surveyed the original Engineer Claim Group, in 1905 (Brook) and, thus, was very familiar with the location.
Alexander gained control of the Engineer Group, with partners in 1906. There were contentious issues for a while during this period with litigation, subterfuge, curses and surreptitious claim staking (Brook) (Mauthner, 1996) but work continued on the property so that by 1910, Captain Alexander had a two stamp mill working at the Level 1 of the property (Hougen).
By 1912, Alexander had sole ownership of the Engineer Mine and systematically explored and mined the property. He developed the upper levels of the underground workings and processed over 2,000 ounces of gold over several seasons (BCGold, 2012). In 1918, Captain Alexander had arranged for a possible sale of the Engineer Mine to Mining Corporation, a prominent Canadian Mining Company of the time, and traveled back to the mine with representatives of Mining Corporation. During that trek, Captain Alexander, along with 353 other passengers, including his “wife” and two of the Mining Corporation men, died aboard the Steamship Princess Sophia when it sank near Juneau on October 25, 1918. After Captain Alexander’s death, several claimants (including another wife in England) appeared with interests in the property, and many years of litigation followed.
The property was finally taken over in 1923 by a New York group and production from Engineer Gold Mines Ltd. began in 1924. Advances at this time were the most significant that the property had seen yet. They included the development of a town site, installation of a power plant on the Wann River with transmission lines to the mine, construction of a concentrator and mill on the lakeshore near the 5 Level portal, and development of the underground tunnels down to 8 Level. Over 140 people were employed at the site.
Visible gold detection was the primary method used to identify and follow ore shoots in veins. Reserves were exhausted by 1927, but development continued with drifting and limited mining until 1933. Reginald Brook, an associate of Captain Alexander, stayed on as caretaker of the property and selectively hand-mined the Shaft Vein. In 1944 a group of miners leased the property and high-graded the veins on the underground workings until 1952 (Mauthner, 1996).
Documented ore production between 1910 and 1952 at Engineer Mine is recorded as approximately 14,263 tonnes at 39.4 g/t Au and 19.5 g/t Ag (18,000 oz Au and 8,950 oz Ag). Underground workings consist of about 5,500 metres of drifts, shafts, raises and stopes on eight levels.
Several exploration companies worked on the property from the 1960s to 1980s, to varying degrees, including Tagish Gold Mines; Nu-Energy Resources Ltd., which sampled the hydrothermal breccia zone along Shear Zone "A" on 5 Level; and Nu-Lady Gold Mines Ltd. In 1987, Total Erickson Resources Ltd. conducted the most comprehensive modern exploration of the property yet completed, including an aeromagnetic survey, detailed geology, and drilling.
Gentry Resources Ltd. optioned the property from Total Erickson in 1989, and acquired title to the property in 1990 with Winslow Gold Corp. Ampex Mining acquired an interest in the property from Winslow in 1993, and through further transactions the property interest was passed to Old Engineer Mining Corp. (now Engineer Mining Corp.) in 1997. Mining and development activities occurred throughout this time and are detailed in Davidson (1998).
In 2007, BCGold Corp. optioned the Engineer Mine property from Engineer Mining Corp.
The goal during my week at the mine was to explore the three working Levels, 5, 6 and 7, for quality mineral specimens. Levels 6 and 7 have been flooded since 1928 and Ampex mining crews worked hard, prior to our visit, to dewater the winze and rehabilitate those levels. As well, I examined other adits, surface excavations and surface waste rock piles in an effort to salvage mineral specimens. I was particularly keen to locate excellent specimens of electrum (a natural alloy of gold and silver) and "allemontite", not a valid mineral but a combination of interlayered and/or intermixed arsenic and stibarsen for which the mine is famous.
My tool of choice for locating allemontite specimens was my metal detector, a White Classic III with a Blue Max 950 coil. Allemontite responds well to this machine with a strong, sharp signal and it was relatively easy to locate pieces in the waste dumps and veins, when they were present. Unfortunately, the waste rock dumps are also laced with scrap metal, particularly nails, wire and spent blasting caps. These proved to be a tiresome nuisance in specimen recovery. They also provided a strong, sharp signal to the metal detector!
I knew that the rich but disseminated, fine-dendritic electrum at the Engineer Mine does not respond to metal detection well and gives, at best, a very weak signal, at very shallow depth of burial. So the only way that I could find gold on the property was with my eyes and rock hammer. How primitive! Some of the Geological staff on site were particularly adept at spotting the electrum in the tell-tale roscoelite fragments. We did find some very good high-grade!
A nice surprise were the numerous vugs and cavities that we encountered in the underground workings. All of the veins are fairly vuggy, at times, particularly vuggy in proximity to the monzodiorite dykes and these openings are always lined with crystals of quartz and calcite. As well, the multi-episodic mineralizing events that created the veins, caused various generations of these mineral to form, including sharp casts of quartz after calcite and then quartz fillings of the casts!, resulting in abundant epimorphs and pseudomorphs of the two minerals, some excellent. I was happy to recover any of these types of specimens.
Level 1 - Dump
I spent considerable time at the Level 1 waste rock dump. This dump is also referred to as “Captain Alexander’s Dump”, since it is adjacent to the stamp mill that Captain Alexander built back at the beginning of the 1900’s. The dump is waste from mining plus the hand-cobbing/sorting of the earliest operations of the Engineer Mine and was the only good source of allemontite that I found at the site. Since my metal detector would only detect allemontite to a depth of 20-30cm or so, Swede Martensson, mining contractor on site, kindly bulldozed the dump twice in order to provide me with fresh material to examine. I was hoping to recover some larger lumps of allemontite but the biggest pieces were only 50mm or so across, with most smaller.
Shaft Vein Dump
We examined all of the surface workings and dumps by eye and with the metal detector. Only the Shaft Vein revealed some very good electrum. No allemontite was found there. Dr. Leo Millonig, a graduate researcher working at the property, found some very high-grade pieces of electrum in quartz/calcite and I found several more.
Engineer Vein - Level 5
Level 5 is accessed by an adit which cross-cuts the Double Decker and Engineer Veins and is the portal to the current operation. The collar of a winze (internal shaft) is located at Level 5 on the Engineer vein and the levels 6 and 7 were accessed using ladders and a winch in that shaft. The shaft had been flooded since 1928 and so, to access the Levels 6 and 7, Ampex mining dewatered and rehabilitated the shaft and timber to a useable and safe condition down to the floor of Level 7. Level 8 was not accessed during this phase of the project. The timber was in pristine condition and required only some new nails and support here and there to be useful and safe. Level 5 was a working-mining level in the old days and extensive stoping was done on both the Engineer Vein and the Double Decker Vein from this level. Although some electrum could be seen in-situ, very little was seen elsewhere on the level since the old stopes, where you would likely find it, were too dangerous to access. A large vug was located in the Engineer Vein about 40m from the shaft and a few nice calcite specimens were recovered from it.
Engineer Vein - Level 6
There was not much to collect mineral specimen-wise on Level 6, although one of the miners found a very good piece of roscoelite/electrum there during my visit. The level holds promise to increase the mineral resource on the property.
Engineer Vein - Level 7
We found two quartz-calcite vugs, one large, one small, on Level 7. The larger vug was lined with drusy quartz crystals that had two different generations of calcite on the quartz, as well as small clusters of 1-4mm pyrite crystals. The smaller vug had just a few sharp, white, hexagonal-tabular calcite crystals in it.
Engineer Vein - Lake Adit
There is an adit that goes 40m or so, along strike, into the Engineer vein on the shore of Tagish Lake, near water level, accessible by canoe. Dr. Millonig noticed a large calcite-quartz vug near the entrance to the portal and collected a rather excellent quartz-covered calcite specimen, with crystals to 12.0cm or so, from it. That specimen is now in the offices of BCGold Corp, in Vancouver. I also collected some specimens from this vug.
Double Decker Vein Lake Adit
Nothing of interest was found at the adit located on the Double Decker Vein at lake level.
Allemontite The literature on the Engineer Mine often refers to a mineral called “allemontite”. Allemontite is not a valid mineral but is really interlayered and/or mixed arsenic and stibarsen, two valid minerals. All of the “allemontite” was recovered from one source, the 100 level waste rock dump adjacent to Captain Alexander’s original mill. None was seen in-situ underground, although some was detected within the veins. See these two minerals for more detail.
In 1917, Captain Alexander donated an unusually excellent example of allemontite and some electrum samples to the Royal Ontario Museum, Toronto, Ontario. Professor T.L. Walker, the first director of the Royal Ontario Museum and professor at University of Toronto, was intrigued by the specimen and undertook a scientific examination of it. He determined that allemontite was not a mineral after all but what he felt was a mixture of two minerals; antimony and arsenic in an interlayered aggregate and wrote a paper about it later in 1921. He was partially correct. It turns out that subsequent work on Allemontite has revealed that it is, indeed an interlayered aggregate of two minerals but the minerals are arsenic and stibarsen (Mauthner, 1996). Stibarsen is a valid mineral, a composition of Antimony and Arsenic –a natural semi-metal alloy, if you will.
Professor Walker made the trip across Canada to visit the Engineer Mine in 1921 to observe the mineralogy of the Engineer Mine, in situ. The mine manager, Reginald Brook collected five condensed milk boxes of allemontite specimens for Professor Walker, who took them back to Ontario (Brook). Nobody knows what happened to the specimens, since none of them were ever catalogued! I wish I that I knew!
Antimony Apparently, native antimony has been found at the Engineer Mine but I did not encounter any. However, I have included a couple of photo s of native antimony as found at the Engineer Mine that are in the collection of L. Twaites. The compositions of the minerals on the specimen have been confirmed by electron microprobe analyses.
Arsenic I found numerous fragments of arsenic, up to 30mm across, in Captain Alexander’s waste rock dump, often with stibarsen. The arsenic is always botryoidal and even if it appears not to be, close examination will reveal concentric banding in most samples. The arsenic can also be recognized by the reddish-purple product of oxidation that usually coats it in weathered pieces. In most cases, when arsenic was found in matrix, it had formed in quartz-lined vugs in the veins, with the remainder of the vug filled with coarse calcite.
Calcite This mineral composes a large proportion of the veins and is often intergrown with the quartz and other minerals. Along with the allemontite, it does seem to be one of the last minerals to have formed in the youngest mineralizing episodes. Excellent crystals with varying morphologies were noted with the largest being rhombohedra to 12.0cm.
Electrum This is the main economic mineral in the veins and the raison d’être of the Engineer mine. Gold is always alloyed with silver and, at the Engineer Mine, in an average ratio of around Au:Ag, 40:60. The “gold” at the Engineer Mine is, in fact, always electrum. The nicest specimens are the beautifully crystallized, dendritic masses in calcite. In those specimens, the calcite can be slightly dissolved away with acids to reveal the crystals of electrum, often associated with crystals of quartz. The electrum usually occurs as beautiful “herringbone” crystal aggregates, branching dendritic forms and wires in roscoelite. Geologists and miners at the mine are always attuned to the “look” that the electrum-roscoelite aggregates have, since it is believed this combination represents the largest volume of the economically important amounts of gold in the veins. Roscoelite always has electrum in it!
Rich leaf gold was found in quartz and calcite, not roscoelite, at the Shaft Vein, during my visit. This has also been found at the nearby Boulder vein.
Quartz This is one of the most common minerals in the quartz-calcite veins. The quartz has various textures due to the multi-episodic nature of the veins. Size of crystals ranges from fine drusy crystals to coarser 10mm crystals lining vugs and casts. Often, the druzy quartz is overgrown on calcite or is a present as a shell after calcite crystals. It is almost always milky or colourless. As well, as previously mentioned, quartz is also present as casts after sharp feldspar (type?) crystals.
Roscoelite This vanadiaum-rich mica-group mineral is an indicator of higher grades at the mine. It most commonly encases the electrum and is, thus, an indicator mineral. Other than hosting much of the electrum at the deposit, it has little interest as a specimen. It has a characteristic dark green, almost black colour that all people at the mine become attuned to.
Stibarsen This relatively rare mineral was present to a greater or lesser extent in the majority of the allemontite that was recovered. It is present as silvery layers within in botryoidal aggregates with black arsenic with the stibarsen often being the last phase in the botryoid. Since many of the specimens had lain in the waste rock dump for 90 years, or so, so many of the recovered specimens showed stibarsen as a white, oxidized layer when first recovered.
Preparation techniques exposed some fresh surfaces on or from within in these specimens. I was hoping to recover more of this relatively rare mineral but we’ll have to wait and hope for a future mining operation to recover fresh, excellent specimens.
To view mineral Engineer Mine specimens for sale, please click here.
The work camp at the Engineer Mine project is not an atypical camp, in my experience but it was unique in a number of ways. I thought I’d include sort of outline of a “typical day” for readers who are not familiar with this type of operation.
The camp consists of the “main building” which is a series of attached modular buildings similar to those at many construction or mine camps. The main building contained the all-important kitchen, storage, dining room, “Dry”(where all of the work clothes and underground gear is kept), shower/laundry and toilets and bedrooms. The bedrooms are built to house four people per room but since there were only six or so of us that needed rooms we each had one to ourselves! There are also a couple of trailers that have been located on the site that some of us stayed in plus a very nice chalet that had been built sometime in the past that can house a couple of people. I didn’t hear anyone complaining about lodging!
One thing that I noticed was that everybody at site was REALLY into their jobs. They lived and breathed mining and geology. The hours were long but even when they weren’t “working”, they were most often thinking about the work, discussing better ways, learning about each others’ jobs, planning ahead, reviewing what has happened, etc.
The camp is a dry camp., ie no (or very little) alcohol. There is no TV at the camp, although there could be. Everyone was pretty pleased to not have television. Instead, we ended up in many excellent conversations, picking guitars, planning work, reviewing progress and events and listening to each others’ stories. Swede always seemed to be in the middle of the story telling! There is very good wireless reception via satellite at the mine and we all could use our Blackberries, I-phones and computers to surf and communicate with the office, home and friends. Bruce Coates, the Project/camp manager ensured that the various duties were accomplished and that everyone worked in a safe manner. The people at the Engineer Mine seemed to get along well and I enjoyed their company very much.
Breakfast happened every morning at 7:00pm sharp. Each day Belinda had an excellent breakfast for us and was quick to accommodate individual food desires and needs. There was always hot coffee ready and a basket of fresh baked cookies beside it. After and during breakfast, at the table, the plan for the day was reviewed and any questions answered or coordination handled. After breakfast, everyone changed into their work clothes and headed off to do their respective tasks –preparing samples, cutting or logging core, mapping, writing reports, tending the pumps, tending the generators, etc. I had all of my underground gear with me and so was self-contained for any type of work. The main emphasis when I was on site was the sampling of the veins underground on Levels 6 and 7 and most of everyone’s activity had to do with that effort. I generally went underground with everyone else and examined the veins and collected minerals on the levels that they were working on or collected at the various sites on surface.
There were four “Quads” or ATVs on-site and that made getting around the site a lot quicker and easier. The boat generally comes in once per week to bring people and supplies and to take out shipments of samples and the people that were at the end of their stint.
Lunch was precisely at Noon hour and everyone came back up from underground or wherever they were working to partake in healthy and satisfying lunch. Great soup! More cookies! After lunch and a suitable break, everyone returned to what they were doing during the morning.
Supper was at 6:00pm and, besides always being a great meal, was a time for excellent conversation, discussion, raising of issues and more planning. Someone always seemed to have some interesting rocks, minerals or gold to pass around for the others to examine. After supper everyone usually sat out on the front deck or in the dining area to read or chat. There were always pumps to check on and other such duties, as well. That continued more or less, off and on, until everyone was sleeping, usually by 11:00pm or so. Then next morning, it started all over again!
The sampling project at the Engineer Mine was an operational success for BCGold and its contractor Ampex Mining. The old 600 and 700 levels were dewatered, rehabilitated and sampled (160 large chip samples!) and are now flooded again. Let’s hope that BCGold returns to these and other levels in the future for further exploration work and perhaps to start a mining operation!
My aspect of the project was also a success. I managed to recover very good examples of electrum, “allemontite”, calcite and various pseudomorphs-epimorphs. My only disappointment was the quantity of allemontite that we recovered. I had hoped to do better. Many of the specimens that I collected or that were supplied by BCGold Corp are for sale on this website. I hope that I will have an opportunity to return to this intriguing old mine sometime in the future.
If active mining is undertaken in the future, I am confident that excellent mineral specimens of electrum, stibarsen, arsenic, calcite, various pseudomorphs and possibly other minerals will be recovered.
It was a pleasure to work with the various people at the site. I sincerely thank all for enabling me to integrate my efforts with their work and for making me feel welcome and part of the team.
The Ampex staff, Swede Martinssen, Paul Wray, Dave Parisien, Belinda Gladish and Mike LeBlanc were not only hard working professionals, they also ranked high in the all-important camp attribute of camaraderie. Swede was one of the most effective leaders that I have seen in a long time, working well with all staff on-site in a safe and knowledgeable manner, always with a sense of humour. Swede has been involved with the Engineer Mine for many years and his understanding of the history and workings helped us all in our work. Mike and Paul (who also runs the Yukon Rock Shop near Whitehorse) were very effective in helping us all accomplish our geological and mineralogical duties safely and efficiently. Belinda the camp cook AND qualified first aid person always had a smile to offer, plus fed us well balanced, delicious meals that we always looked forward to!
The BCGold geological staff, Darren O’Brien, Bruce Coates, April Barrios, Fionnuala Devine and Dr. Leo Millonig (also of University of British Columbia (UBC)) were a dedicated, hard-working lot, also well versed in camraderie. Led by VP Exploration Darren O’Brien and project manager Bruce Coates, they managed to accomplish the gruelling work of mapping and accurately chip-sampling the 6th and 7th levels on schedule. Special thanks to Dr. Millonig who worked at the site and is also doing post graduate geological-mineralogical research on the Engineer Mine veins at UBC for the next year or so. He has a keen eye for detail AND gold, amongst other minerals!
I have thoroughly enjoyed being involved with the Engineer Mine project. BCGold management are to be commended for their willingness to recover unusual mineral specimens to be offered to the world as a legacy of the historic Engineer Mine, its interesting veins and BCGold Corp.
BCGold (2012). www.bcgoldcorp.com. Lots of information on the history and current status of the Engineer Mine here.
Brook, R. Engineer Gold Mine Story. Yukon Archives. A fascinating account of life before and during the Engineer Mine by Reginald Brook who was a close friend of Captain Alexander and mine manager at the Engineer Mine for many years.
Dominy, S. C. and Platten, I.M., 2012. Application of historical data to estimate a mineral resource at the Engineer gold mine, BC, Canada, in Proceedings of the Narrow Vein Mining Conference 2012 (Editor: S. C. Dominy), 81-100 (The Australasian Institute of Mining and Metallurgy: Melbourne).
Hougen www.hougengroup.com/yukonHistory. Hougen Group of Companies, of the Yukon, has a wonderful website full of information on all things Yukon. In particular, please look at this link: http://www.hougengroup.com/yukonHistory/nuggets_year/2000s.aspx?nugget=1965#ENGINEER for their take on the history of the Engineer Mine.
Mauthner, M.H.F, Groat, L.A. and Raudsepp, M. (1996). The Engineer Mine. The Mineralogical Record, Volume 27, p263-273 An excellent paper on this Mine, including much more in-depth look at the mineralogy.
Walker, T.L. “Allemontite” from Atlin, BC (1921) Journal of the Mineralogical Society of America, Vol. 6, No. 6. Walker was the first Director of the Royal Ontario Museum and visited the Engineer Mine in 1921.
Specimens
Figure 22) Native Antimony, Arsenic crystals, 7.0 x 7.0 cm. I didn’t personally see any native antimony during my visit. This specimen has tin-white native antimony and the smaller, darker crystals are crystals of arsenic. The minerals were confirmed by microprobe analysis. L. Twaites photo and collection
Figure 23) Close up of native Antimony from figure in the lower part of the specimen and arsenic crystals in the upper part of the piece. Field of view about 5.0cm across.
Figure 24) Botryoidal Arsenic from Captain Alexander’s Dump, 5.5cm across.
Figure 25) Botryoidal Arsenic in quartz, Captain Alexander’s Dump, 6.7cm across
Figure 26) Calcite crystals, Engineer Vein, Level 7, 5.0cm across
Figure 27) Calcite crystals, Engineer Vein, Level 5, 7.0cm high
Figure 28) Calcite – small crystals overgrown on larger crystals, Engineer vein, Level 7, 6.8cm across
Figure 29) Calcite –later generation of tabular crystals overgrowing earlier, iron oxide coated, bladed crystals, Engineer Vein, Level 7, field of view 15.0cm high
Figure 30) Calcite crystals in a quartz vug, Engineer Vein, Level 7, field of view 7.0cm across
Figure 31) Calcite, three different generations (elongated clear prismatic, iron-tinted scalenohedra and white-grey rhombs) of crystals on quartz crystals with minute pyrite crystals. Field of View 5.0cm across
Figure 32) Quartz-encrusted calcite rhombohedra, Engineer Vein, lake level adit, field of view 11.0cm across
Figure 33) Electrum in quartz, specimen, Governor Vein, 5.0cm across. L. Twaites collection and photo.
Figure 34) Dendritic electrum encased in roscoelite and embedded in quartz, field of view 3.0cm across
Figure 35) Electrum in roscoelite in quartz-calcite vein material, specimen 7.0cm across
Figure 36) Close-up of Figure 35
Figure 37) Electrum in roscoelite and quartz, field of view 3.0cm across
Figure 38) Microphotograph of electrum and quartz, field of view 5mm. T. Balacko collection and Photo
Figure 39) Calcite and pyrite on drusy quartz, Engineer Vein, Level 7, 8.0cm across
Figure 40) Calcite and pyrite on drusy Quartz, Engineer Vein, Level 7, 11.5cm across
Figure 41) Casts of quartz casts of calcite crystals, Captain Alexander’s Dump, field of view 12.0cm across
Figure 42) Quartz casts of quartz pseudomorphs after calcite, Captain Alexander’s Dump, field of view 6.0cm
Figure 43) Quartz epimorphs of calcite crystals, field of view 6.0cm across
Figure 44) Partially oxidized stibarsen and arsenic in quartz, Captain Alexander’s Dump, field of view 5.0cm across.
Figure 45) Stibarsen-arsenic in quartz, specimen 14.0cm across. David K. Joyce collection.
Figure 46) Close-up of Figure 45, field of view 7.0cm across
Figure 47) Stibarsen-arsenic, Specimen 8.0cm across, L. Twaites Specimen and photo
Figure 48) Near Carcross, loading the boat with goods for the trip down Tagish Lake to the Engineer Mine.
Figure 49) Darren O’Brien, Vice President, Exploration for BCGold Corp. Darren knows the Engineer Mine and area geology extremely well and is pursuing both, a full understanding of the high-grade, narrow-vein potential of the property, as well as the possibility of finding a large tonnage, low grade deposit, as well.
Figure 50) Swede Martensson Makes a point during the trip down Tagish Lake. Swede is a great conversationalist and story-teller and never seems to be at a loss for good words.
Figure 51) The scene as we arrive at the Engineer Mine. On the beach, you can see the people waiting to welcome the boat, willing to help or ready to leave on the boat after their time at the project.
Figure 52) One of the old buildings from the original “mining town” that remains standing and in fairly good shape. “P. Burns & Co, Butchers”. Wonder why it managed to stay upright while other buildings have fallen down or rotted?!
Figure 53) Belinda Gladish, the camp cook and head first aid person. Always ready with a smile and good meals and snacks. Belinda and her husband spend half of the year sailing around the world somewhere (their boat is currently moored in Indonesia) and during the summers, return to the Yukon to work. Belinda usually hires on as a cook at mining or construction camps. No wonder she smiles so much!
Figure 54) The back of Darren O’Brien and he and I paddle our canoe along the shore of Tagish Lake to the old adits that are present on the shoreline.
Figure 55) This is the shoreline adit that was driven on the Engineer vein, which you can see on the left side of the adit. The drift was driven in just 50m, or so, as an exploration drift but no actual stoping was done in this location.
Figure 56) This is a look at the big vug in the shoreline Engineer Vein adit. Note the hammer pick for scale. The calcite crystals with a skin of quartz crystals are up to 100mm or so across.
Figure 57) A view of me in the canoe as we left the Engineer Vein. I never got tired of the scenery in the vicinity of the mine! D. O’Brien photo.
Figure 58) A close-up of the poor old mill buildings that were built in the 1920’s. That is the Engineer Mountain peak behind it.
Figure 59) Another view of the old mill buildings at the Engineer Mine, on the shore of Tagish Lake.
Figure 60) One of the original log cabins now used as storage at the Level 5 portal.
Figure 61) The remains of the mill that Captain Alexander built in 1912. The Level 1 adit is just behind it to the right.
Figure 62) Captain Alexander’s “clean-up mill” and crusher. In those days, Captain would put crushed, hand cobbed, high grade into the mill, grind it up with the help of the iron balls to the left of the mill. When the high grade was ground fine enough, he would put a flask of mercury into the mill and then rotate it for an hour while the mercury amalgamated with the electrum. Afterwards, the amalgam was treated to separate the precious metals from the mercury. Apparently, the allemontite was a real problem for the amalgamation and retort-recovery processes.
Figure 63) This is the geology office at the Mine. Two of the geology team are preparing to hop on the ATV to go on to their work for the day.
Figure 64) Dr. Leo Millonig and Darren O’Brien readying to head out to “the field”.
Figure 65) Paul Wray, mine supervisor, lead miner, Yukon/Arizona resident and friend at the portal waiting to go underground during my first day underground at the mine. Note how CLEAN my clothes were BEFORE I went underground? See Figure 59 to see what they looked like the next day!
Figure 66) Dr. Millonig and me waiting to go underground on my second day at the mine. The recently dewatered levels had a black mud in them that really stuck to everything, until it dried out a bit!
Figure 67) Darren O’Brien confers with Paul Wray at the Winze head as they wait to go down the ladders to work on Levels 6 and 7. You can see that the timber is new and was installed by Ampex Mining to serve as support for a winch and to secure the area around the top of the shaft.
Figure 68) Paul Wray and Bruce Coates, project manager, at the Level 5 winze station.
Figure 69) Darren O’Brien, in the “manway” ascending the ladders from the working levels below.
Figure 70) Paz, the camp dog (belonged to geologist April), often tried to follow us underground and had to be chased back out. When not yearning to go underground, Paz had a running battle with the local squirrel population, slept on the deck, chased sticks and, I think, had a thoroughly enjoyable time at the Engineer Mine.
Figure 71) The vug just beyond the winze station on Level 5, in the Engineer Vein. Here we are looking up about 7-8 feet above the end of the re-bar ladder. See figures 15, 26 and 28 for the type of calcite found in this cavity.
Figure 72) Shaft Vein shaft to the left, a vein trench and pile of material from the vein trench. We found some fairly high grade electrum on this pile.
Figure 73) In this photo, near the bottom-left of the photo, you can see an old stope that broke through to surface. The Juneau Ice Field, I believe, the second largest ice field on the North American continent, is in this mountain range not far behind the mountains that you are looking at.
Figure 74) Paul Wray contemplates the sunrise scenery out of the dining hall window as he has his morning coffee. If you are ever in Yukon, Paul owns the Yukon Rockshop, located just outside of Whitehorse, which is open during much of the non-winter year. Lots of interesting minerals and ores, especially from the Yukon.
Figure 75) Dr. Leo Millonig tries his hand on the metal detector. He found a nice chunk of allemontite! We’re very interested to learn what Dr. Millonig learns from his studies of the geology and mineralogy of the Engineer Mine area.
Figure 76) Mike, Leo, Swede, Darren and Bruce wish us a farewell, as we depart the Engineer mine on our way back to Carcross. The day before, since the sampling project was completed, the pump was decommissioned and pipes removed from the shaft for the season and the underground workings started to fill with water again.
Figure 77) A gorgeous sunny day for our trip to Carcross.
Figure 78) As Paul Wray said on the trip out, “People pay good money for a boat ride like this!”
Figure 79) The blue colour of glacier-fed lakes, always amazes me!
To view mineral Engineer Mine specimens for sale, you can click here.
Cubanite is a relatively common constituent of sulphide mineralization containing copper. For instance, most people think that all of the copper recovered in the giant Sudbury mining area is from chalcopyrite. It has been estimated that, actually, up to 15% of the copper recovered, originates from cubanite in the ores. The ores are composed of massive sulphides and the cubanite occurs as masses or as crystals frozen in chalcopyrite and pyrrhotite.
Probably other occurrences of massive cubanite are overlooked because cubanite is mistaken for chalcopyrite. In massive form, they look fairly similar and a simple chemical analysis would show copper, iron and sulphur just as you would expect from chalcopyrite..... if you weren't expecting something different.
Although massive cubanite is fairly common, well crystallized crystals of cubanite, are relatively rare and are much sought after. Most collections, even major institutional collections, have well crystallized cubanite from, perhaps, only a few localities. The author was surprised to come across well crystallized specimens from seven different localities within Canada.
The various localities exhibit a broad diversity of morphology from equant, to prismatic, to acicular as well as twinned and untwinned. Such a broad range of morphology is not what most people expect of cubanite. Most people think of cubanite as the tabular, twinned crystals typical of Chibougamau, Quebec or the Sudbury area. It is true that somewhat elongated crystals are known from Morro Velho (Fig. 2) but they are fairly rare and not well represented in private collections.
Cubanite has such a diversity of habits that there could very well be cubanite crystals in many collections that have, before now, been mistaken for other minerals. The purpose of this article is to draw attention to the various forms, geological environments and mineralogical assemblages that well formed cubanite crystals have been found in and, hopefully, to stimulate analysis of specimens in collections. This will probably cause more localities to be discovered and result in specimens being identified properly.
Henderson II Mine, Chibougamau, Quebec
History: Cubanite from the Henderson No. 2 Mine is well known and the occurrence has been well recorded (Levesque, 1983). We will not go into detail here other than to say that the Henderson No. 2 Mine was reported closed (Levesque, 1983) in 1982 but in fact, the mine reopened again in 1984, then closed again in 1989. Additional specimens were recovered during that time.
Geology: The ore at the Henderson No. 2 Mine occurs in a shear zone and subsidiary fractures in altered anorthosite. According to Levesque(1983) there are numerous faults that are parallel to or cut across the main ore zone. Some of the shear zones are open and contain euhedral crystals of cubanite and other minerals.
Minerals: There are a number of different minerals in the open shears and according to Levesque (1983), they include calcite, cubanite, pyrite, sphalerite and siderite. Pyrrhotite and quartz have also been observed by the author.
The Henderson No. 2 Mine is the source of some of the world's best cubanite crystals. It has also been the most prolific with many excellent specimens recovered over the years. Most major collections have a Chibougamau cubanite in them. The crystals are often very sharp and unusually large with crystals being reported up to 3cm across. In addition, the lustrous brassy yellow colour contrasts with white calcite crystals or a plain coarse massive pyrite making the specimens a visual delight.
The crystals that occur at the Henderson No. 2 Mine all seem to be twinned and excellent photographs appear in Levesque, 1983,. Crystals are often “sixlings” composed of three intergrown crystals (figs. 3 &4). Some crystals appear to be twins composed of two members twinned on (110) (fig. 5).
Strathcona Mine, Sudbury, Ontario
History: The Strathcona mine is a large underground Ni/Cu mine operated by Xstrata (formerly Falconbridge Inc.), near Sudbury at Levack, Ontario and has run continuously since 1969. In the past, excellent crystals of cubanite have been found at the mine and they include some of the largest examples of this mineral. The production of specimen grade pieces, though, has not been prolific in recent years. Cubanite crystals have also been found at the Frood Mine in the past (Peacock and Yatsevitch, 1936), also associated with the Sudbury Igneous Complex but none have been recovered in recent years, to the best of our knowledge.
Geology: Much has been written about theorebodies associated with the world famous Sudbury Igneous Complex. Briefly, the complex of rocks intruded into a meteoric impact site. Subsequent cooling of the magma formed discrete layers including quartz norite at the base, gabbro and then a granophyre cap (Naldrett, Rao, Evenson, 1986). During cooling and subsequent events, bodies of massive sulphides were formed and modified. There was much post intrusion metamorphism and subsequent movement of rocks as the complex cooled and contracted forming shear zones and faults.
Minerals: Cubanite crystals are usually found associated with calcite and pyrrhotite. The crystals are, generally, of equant to tabular habit and almost always twinned. They rival the Chibougamau crystals as the worlds finest and probably were the best until the specimens from the Henderson II mine began to emerge (Photo of ROM large crystal). There is an excellent photograph of a micro crystal from this locality in V. Anderson's "Microminerals" column in the Mineralogical Record, Vol 13, p. 109.
Thompson Mine, Thompson, Manitoba
History: The cubanite occurrence at Thompson, Manitoba is the Thompson Mine orebody of INCO Limited's (now Vale-Inco) Manitoba Division. The Thompson Mine has been operating since 1959 and is currently the main source of ore for the fully integrated Nickel-Copper mining/milling/smelting and refining complex at Thompson.
The actual occurrence of the cubanite crystals has not been well documented since the few specimens existing were recovered by surveyors and miners during cut and fill mining operations in the 1980’s. The best crystals appear to have been recovered from the T-l shaft workings at the west end of the orebody (pers. comm. Mr. P. Babulic). More recently, in the 1990’s, small cubanite crystals were collected at the T-3 mine workings (1C orebody) at the east end of the ore bearing zone. Currently, the mining method is highly mechanized, using large open stopes, not the cut and fill stopes where the best crystals were originally found. With this mining method, miners rarely actually see the ore in situ. The only time that it is possible to observe freshly blasted ore or rock is during development of the top and bottom sills of the stopes or the associated development work and therefore the odds of finding specimen grade crystals are low.
Geology: The Thompson Nickel orebody is one of several in the Thompson Nickel Belt. The Thompson Nickel Belt is a linear tectonic feature on the boundary of the Superior and Churchill geological provinces in North Central Manitoba (Pederery et al, 1982). There are a number of rock types in the belt but most of the Ni/Cu sulphide deposits are associated with serpentinites and the rocks that host them; the metasediments and gneisses.
Minerals: The ore at Thompson occurs in various configurations but mineralogically consists of, largely, pyrrhotite and pyrite with smaller amounts of massive pentlandite, chalcopyrite, millerite, cubanite, small amounts of sphalerite with various silicates and, as well, several carbonates. There are localized high arsenic areas which contain gersdorfite and nickeline. Well crystallized sulphides, with the exception of pyrite and millerite, are extremely rare at the mine.
The cubanite at T-3 mine occurs in a vuggy shear zone, outside the orebody, with euhedral quartz, calcite rosettes, sphalerite and minor millerite. It is felt that the minerals in the shear were probably derived from the adjacent orebody and the country rock, remobilized into the shear then deposited during a period
of metamorphism.
History: The Nigadoo River Mine was located near Robertville in Gloucester County, New Brunswick. It was an underground lead-zinc-copper mine in the mid 1960's to the mid 1970's. The author has observed cubanite crystals on only one specimen attributed to this mine.
Geology: The Nigadoo River Mine's orebodies were veins that cut both Silurian sediments and the Nigadoo porphyry. The origin of the veins has not been precisely determined. It is felt (Suensilpong & Stumpfl, 1971) that they could have been derived from the porphyry or parent magma at depth. Alternatively, they were remobilized from deeper deposits during and/or after the intrusion of the porphyry or its parent magma.
Minerals: The specimen carrying the cubanite crystals is not characteristic of the mine's ore. It is composed of scalenohedral calcite crystals speckled with pyrrhotite and cubanite. We do not know what part of the mine the specimen came from or if it came from within the ore veins themselves. It could have come from associated mineralization in the country rock. An interesting feature of the crystals is that they appear to be untwinned. Fig. 10, 11 & 12).
Although the crystals were originally thought to be millerite, the authors suspected that they were not. A simple magnet attraction test on a crystal pried from the matrix proved that they were not millerite and were more likely cubanite. Subsequent x-ray analysis carried out at the Royal Ontario Museum confirmed the suspicion.
Silvana Mine, Sandon, British Columbia
History: The Silvana Mine started producing silver-lead-zinc ores and concentrates early in the last century and has operated off and on again through 1999. Exploration work continues today and the mine is currently operating, again, with ore being milled at the Sandon mill of Klondike Silver Corporation, the current owner of the mine.
Robert Attridge, a former technician at the mine prior to 1992, occasionally collected some micro crystals of various minerals while employed at the mine. Eventually some of these specimens came to the attention of Mark Mauthner, then a student at the University of British Columbia (UBC). The cubanite crystals were initially unidentifued and were subsequently identified by EDS and x-ray diffraction techniques at UBC by Mauthner.
Geology: The Silvana Mine orebodies occur associated with a lode structure in folded, overturned, argillaceous sediments. It is theorized that the orebodies were remobilized from the main original lode into smaller adjacent structures during a period of tectonic activity. That period also caused graphitization and some brecciation. There are open spaces in tension gash-fractures and shear planes (personal comm. R. Attridge) that contain the crystals of interest.
Minerals
Cubanite was one of the last minerals to crystallize in the orebody. The specimens observed contain crystals of cubanite, usually less than 2mm, associated with pyrrhotite, pyrargyrite, pyrostilpnite, quartz, sphalerite, galena, calcite and a chlorite-like mineral. Bladed acanthite crystals were found coating cubanite crystals on one specimen (figs. 15 and 16).
The morphology of the cubanite is unusual in that the crystals are elongated with a very high length to width ratios compared to the "classic" crystals that we are used to seeing. They are deeply striated prisms elongated on {001} and are terminated by simple pinacoid c (Fig. 17). The prism faces are rounded and when in combination with the deep striations the crystals appear "ropey". They are also unusual in that there are no signs of twinning when scrutinized under the SEM.
History: The Gray Rock Property is located near the headwaters of Truax Creek at between 6500 and 6800 feet above sea level near Gold Bridge, British Columbia. The property is of interest because of the quartz veins that are present. These veins were originally explored for precious metals back in 1936 but were never extensively mined. The specimens containing cubanite crystals were originally recovered by Lloyd Twaites, a well known Vancouver collector, and avid hiker. Another collector, Ty Balacko (White Rock, BC), noted strange, elongated, metallic crystals amongst the other minerals and subsequent analyses identified the crystals as cubanite. The analyses were accomplished by Dr. R. Boggs of Eastern Washington University.
Geology: The quartz veins occur in metamorphosed sediments in close proximity to the Bendor Batholith, a uniformly medium-grained granodiorite (Annual Report of the Minister of Mines of the Province of British Columbia, 1936)
Minerals: The cubanite is a late forming mineral in the veins and is relatively rare. Other associated species include quartz, stibnite, tetrahedrite, chalcopyrite, sphalerite, galena realgar, pararealgar, bournonite and pyrite.
The crystals are elongated on {001}, are tapered and occur both as radiating tufts and as individual crystals less than 2mm in length mostly on or partially embedded in pyrite and quartz. The individual crystals appear to be composed of prism faces, prominent because of the elongation on {001} and are terminated by a simple pinacoid (001). Many of the crystals diverge into multiple terminations.
Advocate Mine, Baie Verte, Newfoundland
History: The asbestos mine at Baie Verte is located 6km north of Baie Verte. Mining and production of asbestos fibre began in 1963 and operated with a couple of short interruptions until 1991. The Advocate Mine was a large open pit mine that produced 5000 tons per day of ore plus several times that amount of waste rock each day. The final pit dimensions are approximately 1500m long and 500km wide with a depth of 300 metres.
The specimens of cubanite from the Advocate Mine were originally collected by the author during 1978. They were originally thought to be millerite because of their high length to width ratio and colour and resided in his collection as that mineral for many years. In 1990, a specimen was given to R. Gault at the Canadian Museum of Nature at Ottawa and x-ray analysis revealed that the crystals were cubanite.
Geology: The Advocate Mine is located in the Advocate ultramafic body. The orebody is a serpentinized peridotite and probably formed under conditions similar to those of other asbestos mines in eastern Canada. In short, the highly fractured peridotite acted as a conduit for serpentinizing fluids. The fluids derived magnesia and silica from wall rocks and eventually crystallized out as chrysotile in the fractured, serpentinized host rock.
The cubanite appears to have crystallized in a small area believed to be a fracture zone in the altered mafic volcanics or volcaniclastics just outside the contact with the south side of the complex. Because of the location and the genesis of the ore, it is felt that the filling was post-ore deposition. It was exposed on the south, final wall of the open pit.
Minerals: The cubanite is associated with pyrrhotite, calcite, albite, a brown chlorite mineral and a fibrous silicate. The crystals of cubanite have extremely high length to width ratios, longer than that seen from any other locality. They resemble very fine millerite! The size is usually microscopic but crystals up to 10mm in length were found.
Like the other localities with acicular cubanite, using SEM imaging, the crystals appear to be untwinned with either square or rounded cross sections with prism faces predominating. Terminations appear to be either very flat or obscure. The crystals are deeply striated, so much so, that they sometimes appear to be composed of members in parallel growth.
Some crystals appear to be twisted in a fashion similar to other minerals that exhibit twists due to “screw dislocation” during formation.
In addition to the cyclic twinned habit that cubanite is usually associated with, we have shown that there are additional habits that would not be normally associated with cubanite. The acicular habits from the Advocate Mine and the Silvana Mine are particularly dramatic examples of this type of morphology. The tapered, elongated habit seen from the Grey Rock Property also is atypical compared to the habits normally expected for the mineral.
There is a test that will help greatly to differentiate cubanite from other minerals such as millerite or chalcopyrite – simple magnetism. Cubanite is relatively highly magnetic and a loose crystal will readily cling to a magnet. With small crystals, this phenomenon is easily observed under the microscope. With a sensitive, suspended magnet, crystals of cubanite may be detected while on matrix. Of course, the presence of pyrrhotite or magnetite, which are often present in sulphide ores, would render such a method ineffective and a suspect crystal or fragment should be detached from the matrix if those minerals are thought to be present.
There were many people who assisted the author with the work involved in assembling this article on cubanite from Canada. Although the work was conducted in the 1990’s and many people have changed jobs, retired, or passed on, I would like to thank them all in the present context. Many thanks to those who provided specimens and information from some of the previously unknown localities; the Silvana Mine, Mark Mauthner and Robert Attridge; the Gray Rocks property, Lloyd Twaites and Ty Balacko; T-1 Mine, P.Babulic; Nigadoo River Mine, Dr. P. Von Bitter.
Many thanks to Dr. George Robinson currently curator at the A.E. Seaman Museum, Houghton, Michigan, formerly of the Canadian Museum of Nature for help with SEM analysis and photography of specimens. R. Gault and the late J. van Velthiusen of the Canadian Museum of Nature provided the first X-ray analysis of the Advocate Mine cubanite. Thanks to Malcolm Back of the Royal Ontario Museum for help with x-ray analysis and, both he and Kathy David, for SEM photography. W. Ridley, formerly of ICI Explosives Canada generously assisted with EDS analytical and SEM photographic support. Dr. R. Gait provided very valuable help in researching information and discussion of contents. Lloyd Twaites, Mary Simpson and Malcolm Back helped greatly with improving the contents and quality of the text. Dr. R. Woodside provided valuable guidance and insight into the structure and morphology of cubanite.
SZYMANSKI, J.T. (1974) A Refinement of the structure of Cubanite, Zeitschrift fur Kristallographie, Bd.140, S218-239
ANNUAL REPORT of the MINISTER of MINES of the PROVINCE of BRITISH COLUMBIA (1936), F43-F47
BEALES, F.W. and LOZE, G.P. (1975) Sudbury Basin sediments and the meteoric impact theory of origin for the Sudbury structure, Canadian Journal of Earth Sciences, Volume 12, 629-635
HIBBARD, J. (...?) Geology of the Baie Verte Peninsula PALACHE, C., BERMAN, H. and FRONDEL, C. (1951) Dana's System of Mineralogy, 7th edition, John Wiley and Sons, New York
NALDRETT, A.J., RAO, B.V. and EVENSEN, N.M. (1986)
Contamination at Sudbury and its role in ore formation, in Metallogeny of Basic and Ultrabasic Rocks (lnstitute of Mining and Metallurgy), 75-91
LEVESQUE, A. (1983) Cubanite from Chibougamau, Mineralogical Record, May-June, 151-154
PEACOCK, M.A. and YATISEVITCH, G.M. (1936) Cubanite from Sudbury, Ontario, American Mineralogist. Volume 21, 55-62
PEREDERY W.V. and Geological Staff (1982) Geology and Nickel Sulphide Deposits of the Thompson Belt, Manitoba, in: Precambrian Sulphide Deposits (Special volume 25), Geological Association of Canada, 165-209
SOMMERS, R.E. and WALKER, J.F. (1954) Lode Metals in British Columbia. Report of the Minister of Mines, British Columbia Department of Mines. A104-A105
SUENSILPONG, S. and STUMPFL, E.F. (1971) The Nigadoo River base metal deposit, New Brunswick, Canada, Transactions of the Institution of Mining and Metallurgy, 95-104
TRAILL, R.J. (1983) Catalogue of Canadian Minerals, Geological Survey of Canada, Paper 80-18, 124-125
Dave Van Dieren came to visit me at my home in Kamloops back in 1986. He is a mining and mineral processing engineer and he was starting to develop an interest in collecting natural mineral specimens. He is an avid hiker, and had encountered crystallized minerals during some of his hikes and, also, during a summer job working in mineral exploration. During the visit to my home, he noticed a specimen with small Japan-law twinned quartz crystals, from Peru, and said that he had a larger one that he had found a couple of years earlier. I was skeptical but on the following weekend, on a collecting trip to Monte Lake, Dave pulled out a specimen to show me. Surprisingly, it was a small but well formed specimen of a quartz crystal twinned according to the “Japan-Law” of twinning in quartz. A Japan-Law twin is one where two crystals of quartz have formed together with axes oriented at almost 84 degrees and 33minutes to each other. While quartz crystals are common around the world, these kinds of quartz crystal twins are not! He told me that he had found the quartz crystals while hiking on Foley Peak, in the Cheam Range, near Hope, in southern British Columbia. It is a very close to the Canada-USA border. I suggested to Dave that, if he was ever going to hike to that place again, I would love to accompany him.
A couple of months later, Dave called me and invited me to join him and two other friends on a hike to Foley Peak. On a Friday night in late July of that year, we drove up to within 4,500 feet or so of the peak and camped overnight. In the morning, we woke up to a gorgeous, sunny day and a clear view of Foley Peak and surrounding mountains. I thought, Yikes! we’re going to hike up THERE!?! I was a novice hiker while Dave and his buddies were pros!
We headed off in search of the old mule trail that led to the peak. The trail started in lush coastal rain-forest and, eventually, ended up at the 6300 foot elevation in treeless, “Alpine” mountain terrain, complete with permanent ice fields. Although there are many higher mountains in the world, the sheerness of the climb makes the climb a challenge for any avid hiker. My body was not used to such hikes and I ended up with severe leg cramps and was pretty exhausted by the time we reached our destination, a 4,000 foot vertical climb in six or so hours. The climb, although exhausting for me was super interesting as we passed various changes in vegetation. I got a real kick out of the pikas, a rabbit-related mammal, that inhabited the boulder fields at the start of the alpine terrain.
The destination area was mostly barren rock, ice fields, scrub bushes and alpine vegetation. There were very few places level enough to camp! We, eventually, did find a couple of spots between the boulders for our tents. What a gorgeous place! Amazing scenery in every direction that changed dramatically with the amount of clouds and level of the sun.
Foley Peak has been the subject of geological investigation a number of times in the past, mostly for its copper and gold potential. The location of the Japan-Law quartz crystals is actually a skarn deposit marked by copious amounts of copper and iron oxide staining on the side of the peak. Old geological reports note the mineralization in the area and also point out a “zone of giant quartz crystals” in the skarn. While this zone has very interesting sounding potential, in fact, it is just a zone of very large interlocking milky quartz crystals with no specimen potential, as far as we could tell.
The original Japan-law twin that Dave Van Dieren found was recovered from the talus at the base of a cliff at the edge of the Foley Ice Field. When we had recovered from the climb we made our way to the location and began methodically digging in the talus across the base of the cliff. We recovered a number of twins and many individual crystals. At the time, we assumed that the crystals were from the quartz zone underneath the talus, which was only 0.5m or so thick.
Dave van D. and I decided to return to the locality, later, with better digging equipment plus drilling and blasting supplies.
Second Trip
Dave Van Dieren and I enlisted the help of Bill Montgomery, of Kamloops, BC, for the next trip to Foley Mountain a month later. No hiking this time. Helicopter! We wanted to take my Cobra Drill, explosives, packing material plus camping gear and it would not be possible to pack these materials up the trail. Besides, by hiring a helicopter, which only cost around $700.00 for a round trip, we would have more time for collecting and we’d be fresher, as well!
So in the August of 1987, we headed up to Foley Peak again. Weather was iffy but we finally were able to fly to Foley, through the clouds. As soon as we landed, the clouds moved in, again, and the helicopter was trapped for a while. After a couple of hours, the clouds parted and the pilot flew the helicopter off of the mountain.
We dug across the base of the base of the deposit, again and recovered a few nice twinned quartz crystals, including the largest one, 5.5” across. Dave Van Dieren won the coin toss, at the conclusion of the trip, and selected that large one as his own.
We dug out the talus along the stretch of the base of the deposit right to bedrock which was solid quartz. Trouble is, it was SOLID quartz with very few openings. There were no good crystals in it! We scratched our heads and, after gazing at the cliff above the talus. Duh!!!), we realized that the crystals were originating from large vugs in the cliff above the talus. Actually, the reason that we were finding some crystals in such great shape and not smashed to smithereens on the talus is probably because they fell out into snow and were gently laid down onto the talus as the snow and ice melted.
We did explore around the sides of the mountain but found no other good spots. So we split up the crystals that we had found and decided that we could not collect anymore great twins at the location that trip. We’d have to come back with climbing gear and tackle the vugs high up on the mountain face some other time.
Third Trip
We did plan to return to Foley Mountain a year later. This time, Dave and I enlisted the help of my friend, noted collector, rock climber, caver, gemologist and geologist Brad Wilson of Kingston, Ontario. I took rock climbing lessons in Ontario and Dave was taught rappelling technique by mine rescue workers at the mine he worked at, Highland Valley Copper, near Logan Lake, BC. So Dave and I knew the basics but Brad brought the right gear and the right level of expertise to the venture.
The plan was that we would climb up above the vugs and then rappel down to access them. We would empty the contents of the vugs while suspended on ropes, lowering packsacks of specimens to the icefield below by a separate rope. This system worked well.
Upon arrival, we climbed to the designated spot. What a view!! It has to be one of the more spectacular views from a collecting site! Brad anchored the main rope, with a tension-equalizing knot system, to several scrawny but tough old shrubs that held to the mountain tenaciously. He was the first to go over the edge to have a look at the vugs, clearing the cliff face of loose rock on the way down. We waited for his report on the radio system that we had purchased for the occasion. Brad did encounter three sizeable cavities in the cliff face that contained quartz crystals and actually found a couple of Japan-Law twins on the side of one of the cavities. For the most part, however, the linings of the cavities had collapsed and required careful excavation. Two of the cavities were large enough to sit in once some of the material had been removed. So we took turns rappelling down the cliff face, digging, lowering packsacks of specimens and admiring the view.
This time, many of the twins were pristine. After all, they had not fallen out of a vug to the talus slope below. As well as loose crystals we found several very nice matrix specimens showing a twin amongst many other un-twinned crystals.
In addition to the quartz crystals, there was a fair amount of calcite, often as disc-shaped white crystals to 1.5cm or so perched on and between quartz crystals.
There was also adularia feldspar in heavily striated, twinned crystals, on occasion.
I think the biggest surprise on this trip was the scheelite. Dave van Dieren had noticed that some clear, colourless fragments had a very high density. We weren’t sure what they were but, later, after exposing them to short-wave U/V light, we concluded that the fragments were scheelite. Many were clear enough to be faceted into gems by Brad Wilson and some are figured below.
The three large pockets’ contents were largely collapsed. This made digging relatively easy (once were rappelled down to them) and was accomplishable with a screwdriver, pick, etc. We were careful to not damage any crystals that we found in the rubble, and wrapped any good ones immediately. The good crystals and specimens were carefully packaged in newspaper and lowered in batches to the ice field below. It was great sitting inside the vugs, pulling out top class Japan-law twin quartz crystals. As a bonus, it was also great to pause, once in a while, to out over the ice, valleys and adjacent mountains.
We excavated the collapsed pocket contents of the three large visible pockets and, after prospecting the face, found two more smaller, crystal-filled pockets. These pockets contained lots of individual crystals but only a few smaller Japan-law twins.
We took time to explore the other areas around the skarn. We descended the north face and found large masses of solid garnet, characterized by garnet crystals mashed together.
The north face also is where an adit had been driven many years ago to access the copper deposit from below, probably to facilitate diamond drilling. We investigated the adit and found a large vug in there. Mineralization was different, though. Again, quartz crystals were dominant but in the “adit vug” they were partially encrusted with small feldspar crystals and groups of siderite crystals. Brad wiggled into the vug and collected a few dozen specimens.
We prospected the south side of the mountain but found only one vug and a single decent specimen of quartz was recovered from it.
We recovered, probably thousands of single quartz crystals during this trip, many of which we left behind due to weight restrictions. We recovered only about 30 or so Japan-law twins, large and small, broken and whole, and they were split three ways. Brad won the coin toss and selected the larger specimen that was covered with single crystals, calcite crystals and one large, beautiful Japan-Law twin.
Again, due to weight restrictions and our lack of funds, it was decided that only one person could ride back down in the helicopter with the equipment and specimens. I won that coin toss so the rest were resigned to hike back down the mountain. It was not a fun hike since much of it was in cold, rain and, during the last stretch, in the dark.
Another Trip!
Dave van Dieren did return to Foley Peak with another Dave, Dave Langevin, during the Fall of 1988. They did find a couple more Japan-law twins including the one in figure 45.
Return to Foley Peak, 2009
I had spoken of Foley Peak many times with Lloyd Twaites, well known collector, from Vancouver. He had hiked up there with his wife, Mary, a couple of times, in the past. We sometimes talked about taking a trip up there to see if we could find any more crystals. During 2008 we were considering the effects of climate change on the various ice fields and glaciers in British Columbia and thought that the melting ice could have revealed more pockets at Foley Peak. We decided that the next year, the summer of 2009, we would head up to Foley Peak one more time.
During the winter before, I contacted Dave Van Dieren, the finder of the first twin and asked him if he would like to go, as well. He did! So with our team in place, we started planning. Dave arranged the helicopter and part of the food while Lloyd arranged most of the menu and logistics with great help from Mary. I couldn’t do much in these departments since I now lived a few thousand km away in Ontario. Dave and Lloyd could drive to the helicopter base.
So in August of 2009, we flew up to Foley Peak another time.
As expected, there was significantly less ice in the glaciers and ice fields than before. It was very different! As a matter of fact there was only one small place to land the helicopter this time! With a little more melt, it might not have been possible to land the helicopter. As it was, the ice melted 0.5m, or so, during our four day stay!
There was more talus exposed this time so we sifted through it and found a few more Japan-law twin quartz crystals, mostly damaged. Only one small one was undamaged.
There was one pocket, the “new pocket” exposed at the edge of the north ice field and we recovered some larger quartz crystals, siderite and scheelite from it.
We went back to the adit and collected in one of the pockets in it, recovering a few more quartz-feldspar-siderite specimens. It appeared that someone else had been in it, though, and pickings were slim.
Interestingly, sometime in the last decade or so, a large southerly portion of the rock face of the collecting area had slid and crashed down to the ice field. The slide material seemed to be made up of skarn material and we managed to find some garnet crystals and scheelite (not cut-able) in that pile of broken rock. As well, interestingly, a couple of new cavities had been exposed, up on the cliff face, as the rock has fallen away. Unfortunately, the rock above the cavities is extremely unstable and it would be foolhardy to try and access the new cavities from either below or above. I’m sure there are some nice crystals in them, though!
The reason that we went back to Foley Peak was to take advantage of “global warming” or Climate change. We thought that we might as well take advantage of an upside” of the warming trend affecting the world! We were not expecting one observation, though!
In some places, there was probably 30 or 40 feet less of ice and snow compared to the last time we were there, 22 years ago. This visit, there certainly was more white on our heads and certainly LESS snow and ice in the ice fields and glaciers. We went there to see what the receding ice had revealed in the geology of the area. What we weren’t expecting was to find other things where the ice and snow had been. At one spot, where there had been 40 more feet of ice and snow, we found a neatly stacked pile of empty fuel drums! These are drums that had been stacked there during the 30’s and/or 40’s, we think, when they did prospecting and small production mining at the site. In other words, the snow and ice levels, now, are at the SAME levels as they were back in the 30’s and 40’s. Actually they are still higher since many items, tools and building foundations were still poking out from under the ice! Maybe the world is warming. I guess it warmed before and then in the succeeding decades, cooled again. And now it is warming again! When we looked closely at the old maps from mining reports, we could easily see that the snow and ice levels, currently, are the same as they were way back then. Interesting. ARE we in a period of long term global warming or are we just getting excited about the normal ups and downs of the climate? I have included some “before” and ‘after” images, below, to show you some differences in the ice/snow levels then and now.
The scenery was a little less dramatic this trip since the air was thick with smoke from forest fires many miles away. One day, the smell of wood smoke was palpable and the scenery was totally eliminated! We could not see anything from the peak for much of the day.
Weather was mostly pretty good and we had lots of sunlight. One night though, a horrendous windstorm erupted and lasted most of the night. I thought we’d be blown off of the mountainside in our tents! The wind lasted through the next morning(under clear skies) until it abated.
We were surprised, this visit, to see various mountain goats above us, grazing on grass here and there on the peak. We were a little concerned when occasionally, they would send landslides of rock careening down the mountainside, mostly down the ice field beside us. See Fig. 50. It would have been extremely treacherous to be caught in one of those slides, with death or serious injury a real possibility. Anyway, it was very cool to see those critters jumping around impossible, treacherous, rocky slopes way above us. We saw none in the three previous trips. They were the only animals that we saw up there, this trip, besides hummingbirds.
Maybe it was because of the receding snow and ice but there were nice wildflowers everywhere. Lots of bumblebees, too. I don’t remember wildflowers other than heather on the previous trips.
The fourth trip to Foley was not nearly as successful in terms of collecting, as the previous trips but it was fun and was a great place to collect. Dave van Dieren and Lloyd Twaites are great collecting companions.
So that ended our recent trip to Foley Peak. Will we go back again? At the present time, there is probably very little to collect. In the future after more ice has melted (if it melts) and after the rock slides have stabilized (in our lifetime?), maybe we or someone else might find some additional nice crystals!
Acknowledgements
I really do not know who took most of the earlier photo’s but suffice to say some are by me, Dave Van Dieren or Brad Wilson, with some by Canadian Museum of Nature personnel, thus the different styles and formats. The earlier photo’s were copied from 35mm slides and so the resolution is not as consistent it would be with fresh digital images. I won’t try to put photo credits on any photo’s other than from the last trip. Thanks to all photographers!
One of my favourite collecting spots is the howlite locality at Iona, Cape Breton Island, Nova Scotia. It is the only place in the world where you can collect superb, macro howlite crystals. Note that the type locality is near Windsor, Hants County, Nova Scotia. This is a different locality.
On a good day, this locality is absolutely gorgeous with aquamarine, crystal-clear, blue water, white gypsum cliffs and great howlite crystals. On a bad day, especially when the wind is blowing from the south or south west, the locality is a dangerous, miserable spot where you are pounded by 1-1.5m waves. Collecting is impossible in these conditions. The thing is, it can change from beautiful to torturous in a matter of minutes. I’ve seen it happen several times!
The deposit at Iona is unique. At Iona, a large bed of gypsum/anhydrite outcrops on Bras d'Or Lake as a white cliff about 17m high, within beds of other assorted sediments. These white cliffs, at the base, are solid, hard, blue-grey anhydrite. When touched by seawater, the anhydrite rapidly turns into gypsum, one of the softest, flakiest minerals known. As the waters of Bras d'Or Lake wash against the white cliff at Iona, it is continually changes the anhydrite to gypsum which subsequently flakes off due to the continuous massaging of the water. Over time, the white cliff is undermined and every few years, small or larger portions of the cliff tumble down into the ocean. The remnants of the cliff, as boulders of gypsum or anhydrite are slowly broken down by the same waters that undermined them. Eventually all traces of the caved cliff are gone and the water begins to undermine the cliff, again. This same mechanism is the mechanism that reveals the howlite crystals and enables us to collect them.
The howlite crystals are embedded in sold anhydrite. When they are in the anhydrite, if you can find any, they are un-extractable. They are extremely fragile and the anhydrite is extremely hard. At water level and only at water level the process to reveal the howlite crystals takes place. As the water in the Bras Dor Lake laps against the boulders in the water or the cliff face, it gently converts the anhydrite to gypsum which is subsequently knocked off of the rock surface by the wave action and presumably dissolved. If howlite crystals are present, then they are slowly and delicately exposed to the air. The clusters start out as a single termination poking out of the anhydrite. Slowly, as the anhydrite/gypsum is removed by wave action more and more of the howlite is revealed until a beautiful cluster of howlite crystals is exposed. The process continues until the cluster of howlite is totally exposed and then falls off into the water to be ground up between the rocks n the water. This process is continuous and unstoppable.
Most people are used to seeing howlite as rounded, cauliflower-shaped, compact masses or nodules. These masses are often compact enough to be used for lapidary purposes. There are crystals of howlite found at Tick Canyon, California (Murdoch, 1957) but they are sub-millimeter in size. The howlite crystals at Iona are very different and are the world’s finest.
Howlite occurs at the Iona locality, mostly as radiating clusters of howlite crystals up to 19mm in length and several mm wide. The crystals are show several forms including two monoclinic prisms and two pinacoids. Crystals range in colour and clarity from perfectly colourless and transparent to opaque grey-chocolate brown, presumably coloured by clay or anhydrite/gypsum inclusions and possibly hydrocarbons. Interestingly, the size of the crystals enabled proper hardness tests to be done. Most references show howlite to have a hardness of 3.5 or so. Tests done on crystals of howlite from Iona reveal that howlite actually has a hardness of 6.5 (Joyce et al, 1993). This discrepancy could be because previous tests were done on the non-crystal, fine-grained nodules of howlite commonly found elsewhere.
To collect howlite crystals you need to either wade in the water around the barren brown cliffs to the base of the white anhydrite/gypsum cliffs or scale the cliffs at a spot beside the railway tracks to access the water level where the howlite crystals are found. Both ways can be dangerous and should not be attempted unless you are fit and physically stable.
At sea level, you could find howlite crystal clusters attached to the anhydrite up to one metre or so above the water level. The tide at this locality is 0.33 of a metre or less and barely noticeable. Generally, the crystal clusters are sparse and usually well separated from each other. Crystals are collected by chiseling pieces of anhydrite off of the cliff face or off of boulders that sit in the water. There is no way to collect at this locality and stay dry. You must wade in the water to access the crystals.
Howlite crystals vary in size and delicacy. The clusters of larger, thicker crystals are very sturdy and can be wrapped and packed for transport. Most clusters, though, are composed of thin-bladed, delicate crystals that need to be carefully wrapped and transported to ensure that the crystals are not damaged. I generally try to trim the specimens on-site so that I can pack each in its own container, so that the crystals are not touched by wrapping materials.
The location at Iona is beautiful and is the location of the worlds best howlite crystals. It can also be a dangerous place of steep cliffs buffeted by high winds and waves. Timed right, a visit to Iona can be a great collecting experience.
Joyce, D.K. Gait, R.I. and Sturman, B.D. (1993) Howlite from Iona, Nova Scotia Short paper presented at the Rochester Mineralogical Symposium, Rochester, New York, 1993
Murdoch, J. (1957) Crystallography and x-ray measurements of howlite from California, The American Mineralogist, 42, 521-524
Sabina, Ann P. (1964) Rocks and Minerals for he Collector: Bay of Fundy Area: New Brunswick-Nova Scotia. Geological Survey of Canada Paper 64-10
Mamainse Point has long been known as a source of copper, in particular, native copper. Since the earliest times in North America, prospectors, explorers and miners have visited the shores of Lake Superior in the Mamainse Point area to search for or mine native copper or sulphides of copper. While the deposits are nowhere near the economic significance of the famous Keweenawan copper deposits across the lake in the Upper Peninsula of Michigan, USA, they have sustained a number of economic mining operations over the years, for various lengths of time, including the Copper Creek Mine and the Tribag Mine. The Mamainse Point area is just an hour or so north of Sault Ste Marie, or “The Soo” as it is affectionately known to Canadians.
The earliest miners were aboriginal peoples who had been finding copper in the area for, probably, centuries before Europeans visited the area. Jesuit missionaries, in the 1640’s noted that natives of the area had been using copper for some time for arrows, knives, and ornaments (Kutz, 1998). The Quebec Mining Company was formed in the 1840’s to mine copper in the vicinity of Point aux Mines, on Mamainse Point and Michipicoten Island, further west. The Quebec Mining Company name is noted on old claim maps of the area.
Alexandre Henry, an Englishman, worked a copper deposit on Mamainse Point in 1770 (Kutz, 1998). Unfortunately, the venture was not successful! Thankfully, his efforts drew attention to the copper deposits located in the area.
Throughout the centuries since that time, various groups and individuals have extracted copper from the Mamainse Point area. I was first intrigued with copper specimens from the area that were found by R. Mielke, of Waterloo, Ontario and his father, around thirty years ago and then, more recently, during 2007. Another acquaintance, J. Paul of East Camden, Ontario found some very well crystallized copper in that area of Lake Superior about 25 years ago. Many other collectors have sporadically found well crystallized copper in the Mamainse Point area over the years, including Gil Benoit and Roger Poulin of Sudbury. Roger and Rita Smirle and Peter Lickley had collected there in the past, as well.
One of the latest groups to visit the area consisted of Roger Smirle of Haileybury, Raymond McDougall of Toronto and me, David K. Joyce, Newmarket, during the fall of 2007 and Spring of 2008. Prospecting and collecting has been made easier, in the last five years, by very low water levels in Lake Superior, due to low snow pack and rain levels in the Lake Superior watershed. Most people consider this to be an environmental disaster precipitated by “Global Warming” and “Climate Change”. Mineral collectors have welcomed the (hopefully, temporarily) low water levels -5 feet or so below “normal”, whatever normal is in a geological timeframe. The low water conditions have left calcite veins, some richly endowed with native copper and chalcocite, high and dry on the rocky shores. Shoreline that was under five feet of water a few years ago was easily accessible in May of 2008 and the fall of 2007!
In addition, there are old mines present in the area, near and on the Shore of Lake Superior or further inland. The old Copper Creek Mine was of particular interest to our collecting group.
The Mamainse point area is largely composed of volcanic rocks; volcaniclastics, amygdaloidal basalts and sediments, covered more or less by unconsolidated Pleistoscene sediments. These rocks are criss-crossed with calcite/silicate veins and hydrothermal fracture systems that often are richly endowed with copper mineralization. The copper is usually in the form of “native” copper or, other times, chalcocite, bornite or chalcopyrite. Only the elemental copper has had much collector interest besides some micro or massive sulphide specimens.
Our prospecting technique was to, simply, hike the shoreline in search of veins that outcropped on the shore. Recall that the shore is very different now than it was five years ago because of low lake levels and the resultant newly exposed shoreline. Lots of newly exposed shoreline!! Although hiking conditions could be rugged, at times, and there were WAY more barren veins than veins with copper in them, it was a pleasant search.
The scenery on this eastern shore of Lake Superior is beautiful. The water is clear, the trees gorgeous and the fact that we collected in late fall and early spring meant that there were few or no black flies or mosquitoes to distract us from the beauty of our search area.
The preliminary trip to Mamainse Point in the late fall of 2007 proved to be successful in locating copper on the shore of Lake Superior. Copper is actually plentiful on the shore and it is easy to find hackly masses. Crystallized copper, however, is much more difficult to come by! Roger and I found a vein just north of Batchewana Bay that had large, rounded crystals of copper. Although the crystals were not sharp, they were thickly deposited and impressive. Unfortunately, these large copper crystals were embedded in both calcite and silicate (quartz and zeolites?) and so were a challenge to expose in matrix (Fig. 33 & 35).
During the Spring trip to Mamainse Point, we found that the water level was 15cm or so higher than it had been in the fall. Makes sense!! There had been very heavy snow fall during the winter and high rain levels during the Spring.
In the Spring we found numerous exposures of copper-bearing veins on the shoreline. A number of the veins (Fig. 7) were solid chalcocite, sometimes with chalcopyrite up to several inches across. Others held leaf copper and, a few, dendritic copper.
Every vein seemed to be different with a varied number of habits of crystallization. Veins that did have nice copper were shallowly excavated with simple hand tools and loaded into packsacks to be worked on later. The basalt host rock was very tenacious after a depth of a few cm.
The copper crystals seem different in every specimen from each different vein. Some were sharp cubes, while others were rounded crystals, thick dendrites, thin dendrites, filigree copper (Fig. 24), to leaf copper.
In the vicinity of the vein with very coarse, rounded copper crystals, copper nuggets were found in depressions in the rock. These were easily located with a metal detector. They were rounded and water-worn but from the look the habit that they exhibited, they were definitely from that vein.
In addition to the copper, well-formed, nicely coloured agates and amethyst can be occasionally found on the shore, as well. D. Joyce did find one very nice light-lilac coloured agate during the search for native copper.
As one would expect, zeolites were encountered in the amygdaloidal basalts, as well as veins and breccias. Although of mineralogical and geological interest, unfortunately, no excellent quality zeolites were found.
We visited the Copper Creek Mine which has not operated for a couple of decades. When R. Smirle had last visited the mine, twenty years ago, there had been a watchman and full mine/mill facilities on site. When we visited in the fall of 2007, there was nothing except a capped shaft. All buildings and dumps had been leveled and bulldozed in preparation for reclamation. The current owners are primarily interested in logging the area and have fixed up roads to facilitate that endeavour.
On the main access to the mine area, the loggers had turned up a copper showing that consisted of chalcocite and native copper (not together) in volcanics. The copper was in a small calcite pod (Fig. 10) in a large boulder that had been turned over by the side of the road and, as well, in-situ, in bedrock, at the same location. We were able to remove some of the calcite-copper from the boulder and bedrock, and, after judicious treatment with sulfamic acid, were able to expose very nice dendritic copper. The copper appeared to be in two generations of growth with the first being delicate fronds of filigree copper consisting of stacked octahedral (Fig’s 35, 37, 37). The second generation consisted of rounded cubes of copper scattered on the first generation copper or on a fine quartz druse that sometimes occurred on the first generation.
Collecting at the mine-site dumps did result in the recovery of some chalcocite specimens with small crystals, massive chalcocite, micro malachite and quartz crystals. Zeolites, calcite and hematite were noted but none that were of high quality.
There are very old workings at Copper Creek Mine consisting of old dumps near adits of old shafts. Near one of the old adits, a showing of copper crystals, in situ, had been located by R. Smirle twenty years ago, on the side of Copper Creek, itself. Some specimens had been removed at that time, and the remainder of the copper was excavated during our May, 2008 visit. There was not very much recovered but enough to provide several good crystallized specimens to each of us. In these specimens, the copper is in a dendritic form consisting of stacked, odd crystals that appear to be twinned octahedra (Fig’s. 26-31) that look like hoppered, dodecahedra. They are octahedra in an interpenetrating twin configuration at 90 degrees to each other. Wonderful! These crystal aggregates were in either calcite or a silica matrix. The ones in the calcite were easily exposed utilizing acetic acid. Sulfamic acid seemed to be very corrosive to these crystals since the surfaces of the crystals are partially weathered to cuprite.
We did not hit any “bonanzas” but we did find some worthwhile copper crystal specimens. There will be copper to collect on the shores of Mamainse Point for the foreseeable future, particularly when water levels are low in the future. Erosion due to ice action, freeze-thaw cycles will further expose old veins for future collectors. If any old mines are re-opened or new mines started, these will no doubt result in some very good quality copper and associated minerals being recovered.
I’ve always liked the idea of living in Nova Scotia, since I graduated from the Haileybury School of Mines many years ago and have had the pleasure of visiting this beautiful province of Canada many times over the years for business and pleasure. I’ve never had the opportunity to live there but my son Daniel now lives in Halifax, Nova Scotia! This gives me an extra incentive to visit that splendid part of Canada, at least yearly. While there, we always try to do some mineral collecting. To me it is the perfect place to collect minerals. It can provide all of the ingredients of a successful mineral collecting endeavour: relatively accessible localities, beautiful scenery and great minerals!
The collector community in Nova Scotia has been very generous in sharing their knowledge of Nova Scotia minerals and the various localities. Terry Collett, dean of Nova Scotian collectors, from Dartmouth, NS, has assembled a spectacular collection of crystallized minerals from Nova Scotia, including many excellent coppers specimens. Terry, along with Doug Wilson (Wilson Minerals) and Ronnie Van Dommelen (Mineralogy of Nova Scotia, http://nsminerals.atspace.com ) are the “ambassadors” of mineral collecting in Nova Scotia, each one, helping interested people in their own way to learn about or collect minerals from this beautiful province. These men regularly scour the surface of Nova Scotia for great mineral specimens and are very knowledgeable.
As you may know, I have always been interested in “native elements”, elements that occur in nature in their pure form. I’ve known about the excellent arborescent native copper from Cape D’Or area for many years and have now had the opportunity to visit that locality twice and collect some very nice copper as well as other minerals. There are several places where you can collect copper crystals and I have visited what is arguably the best, the site near the old Colonial Copper Mine. I’ll just refer to it as Cape D’Or or “the locality”, etc., for the purposes of this article and will focus just on this spot, just east of Horseshoe Cove.
All of the site photographs in this article were taken on a trip to Cape D’Or with Terry Collett, Daniel Joyce and Miriam Moren in June, 2010
There is no easy way to access the locality. Access is either by boat or by making your way down the very steep mountainside and finding a gap in the cliffs. It is possible to hire a fisherman or other local person to take you there by boat. The trip down the mountainside is precipitous and ropes and ladders are very helpful. Either way, you REALLY need to coordinate your visit with the tides. The tide here is 17 metres (50 feet) and when it comes in, it is fast in places and can be very dangerous to be trapped along the base of the cliffs when high tide is approachng! You need to plan your trip so that you arrive at the base of the cliffs just after the tide is going out and then ensure you are out of the area before high tide occurs six or so hours later. Tide tables for all areas around the Bay of Fundy are available in the internet. Timing is critical!
The locality is located above low tide but below high tide beneath the old workings of the Colonial Copper Mine which was an underground mine that operated for a short time during the late 1800’s and early 1900’s. It is possible to collect native copper crystals from outcrops at the base of the cliffs that contain the old drifts, shafts and stopes. Old workings can still be seen on the face of the cliffs as they are slowly eroded by freezing/thawing and incessant pounding by the Bay of Fundy.
You’ll notice from the photographs that the shoreline is composed of rough jagged rocks close to the cliffs and rounded cobbles and boulders further away from the cliffs. The point is that rocks are constantly falling from the cliffs as they are undermined by the Bay of Fundy. You MUST be very careful when approaching or very close to the cliffs. Falling rock is a real hazard, especially in the spring time, early summer and during after rainfalls. Very much akin to standing beside a freshly blasted quarry face. High risk. A hard hat and lots of care are recommended.
The rock at Cape D’Or is basalt, many flat lying flows of Triassic age, as it is in most of the mineral collecting locations around the Bay of Fundy. The basalt at this locality has had hydrothermal solutions percolating through the joint planes (fractures) in the basalt. Where the solutions have percolated through the joint planes, the basalt has been altered to chlorite. Zeolites, calcite and native copper have been precipitated in the joints. The copper is usually embedded to some degree in chlorite but also often in the zeolites.
In addition, these lava flows have amygdules or vesicles, ancient bubbles in the lava that are always filled or partially filled with minerals, particularly silicates of the zeolite group. New cavities are constantly being exposed as the Bay of Fundy wave action undermines the cliffs causing rock falls and/or as frost action loosens rock joints causing rock falls.
The basalt outcrops need to be examined to locate traces of copper in fractures, in the basalt. To collect in at the locality, it is necessary to break out the blocks of basalt, to expose the fractures that contain the copper and other minerals. This can be accomplished by driving wedges or chisels into fractures under or behind blocks of basalt to eventually force or pry them out. If there are copper crystals present, they will be attached to the block that you have pried out or on the rock that you left behind.
The copper is usually pristeen and coppery coloured if it has been encased in the chlorite and zeolites. Sometimes it has a tinge of green from oxidation and other tinmes is very red due to a thin coating of cuprite.
Sometimes the copper peels right off of the basalt and will appear as a sheet of dendritic copper with chlorite and/or zeolites between the dendrites. The chlorite is relatively easy to remove from the copper with a needle or dental picks. Careful, though! The copper is often very delicate and easily bent and broken even under fairly slight pressure. Sometimes the copper will be attached to the rock and the trick is to remove enough of the chlorite and/or zeolites to expose the copper without causing it to fall off the basalt matrix. This is difficult to do and, thus, the majority of specimens do not have matrix! It is best to transport specimens home to work on them carefully under magnification and good light to best expose the copper.
There are other minerals in the vicinity of Cape D’Or. The only other mineral of significance that I saw at the copper location was stilbite in veins and amygdaloidal cavities. Further along the coast very nice specimens of mesolite, stilbite, gmelinite and apophyllite can be collected, at times.
Here are some images of the area, along with specimens to give you a better visual idea of the area and specimens.
Cape D’Or is a beautiful, if not somewhat difficult place to access and collect nice native copper specimens. Access is by boat or descent down the sides of the Cape. Good luck if you want to give it a try!
Again, thanks to Terry Collett, Ronnie Van Dommelen and Doug Wilson for their generosity and knowledge of the Cape D’Or area.
Mineralogy of Nova Scotia, http://nsminerals.atspace.com , Excellent website, R. Van Dommelen
The Cobalt-Gowganda Silver mining area (Cobalt Camp) of Ontario was one of the most prolific silver mining areas in the world. Over 600 million troy ounces of silver have been produced from mines in the area since the first vein was discovered in 1903. I am fortunate to have visited this historic area many, many times over the years. My first visits were when I actually lived there, while attending the Haileybury School of Mines, in the mid-1970’s. It was easy for us to hitch-hike or drive the few miles from Haileybury to Cobalt and wander around in the woods looking for old mine dumps, silver and arsenide specimens, building foundations and the head frames that were still standing.
In 2012, I was fortunate to have co-authored an article published in the Mineralogical Record (Volume 43, #6), with staff from the Royal Ontario Museum, that should stand as a significant reference about the mines and minerals of the Cobalt Camp. This article will no doubt have some overlap but will also introduce a more personal review of my experience with this fascinating mining and collecting area. As well, I will try to feature additional pictures of interesting mineral specimens that have never been published before from my and others’ collections. Unlike the article In the Mineralogical Record that features many specimens that were recovered from active mines in the “heydays”, never to be seen again, many of the specimens featured in this article (not all) were found recently and similar specimens could certainly be found again.
Cobalt is located due north of Toronto and is about a six hour drive on good paved roads from Toronto. The silver mining area is located, mostly, on the western shore of Lake Temiskaming, in Ontario, on the border with Quebec, although some of the mines were located further away near Gowganda, New Liskeard and Elk Lake.
General Geology
The silver deposits of the Cobalt-Gowganda area occur along the northern and eastern margins of the Southern Province in an area referred to as the Cobalt Embayment. The term Embayment derives from the overall “bay-like” shape of this large, approximately 11,580 square miles, an area which is bounded on the north and east by Archean basement rocks and to the southeast by the Grenville Front (Figure 8). A small outlier of Paleozoic strata is preserved at the north end of Lake Timiskaming.
The area is underlain by Early Proterozoic rocks of the Huronian Supergroup which rest unconformably on Archean granitic, metavolcanic and metasedimentary rocks of the Superior Province. The Huronian Supergroup consists of an assemblage of sedimentary and minor volcanic rocks deposited between 2500 and 2220 million years ago and is subdivided into four stratigraphic groups which in ascending order are: the Elliot Lake, Hough Lake, Quirke Lake and Cobalt Groups.
In the Cobalt-Gowganda area the Huronian sequence consists of a variety of essentially flat lying coarse to fine grained clastic sediments of the Cobalt Group which have been subdivided into the Gowganda, Lorrain and Gordon lake formations. The Gowganda formation is subdivided in to the Firstbrook and Coleman members, the Coleman member, predominately conglomerate, laminated siltstone and sandstone, being the most important sediment host to the silver vein deposits. Archean basement rocks are exposed within the Cobalt Embayment as isolated inliers and both the sediments and basement rocks have been intruded by sills and dikes known as the Nipissing diabase. Corfu and Andrews (1986) report a U-Pb baddelyite age of 2219.4+-4 Ma for Nipissing diabase near Gowganda but because of its widespread occurrence throughout the Huronian Supergroup it is not known whether these intrusions occurred as a single event or in stages over a considerable period of time. Compositionally an olivine tholeiite the Nipissing diabase occurs as a suite of gabbroic sills and steeply dipping dikes and plugs. The sills, more accurately described as undulating sheets, maintain a relatively uniform thickness of 980-1100 feet.
Structure
Three major regional scale fault trends occur within the area. They cut all the rocks in the Cobalt Embayment and extend for hundreds of miles cross-cutting the Grenville Front to the south and the Archean basement to the north. Although mineralized veins do occur in these faults they are also found to cross cut them and most regional faults are barren. No clear relationship has been established between the veins and these regional scale faults (Jambor, 1971a).
Metamorphism
The oldest Archean rocks consist mainly of intermediate to mafic, massive and pillowed volcanics and minor pyroclastic and interflow sediments. These rocks were intruded by Archean granites followed by minor mafic, ultramafic and lamprohyric dikes and sills. The metavolcanic-metasedimentary rocks subsequently underwent a regional greenschist-facies metamorphic event and were isoclinally folded. The Huronian strata are mainly flat lying and very well preserved and only exhibit a sub-greenschist-facies assemblage.
Associated with the Nipissing diabase and interpreted to contact metamorphism is an alteration referred to as “chlorite spots or spotting.” Developed mainly in Huronian sediments it also occurs in Archean mafic metavolcanics and mafic plutonic rocks. The alteration appears as dark green spherical, between 0.04-0.20 inches in diameter, aggregates mainly composed of chlorite. Confined to the northeastern portion of the Cobalt Embayment and extensively developed in the Cobalt-Gowganda camp the alteration is highly erratic in its occurrence but is found within 490 feet of Nipissing diabase contacts. Although there appears to be a spatial relationship between “chlorite spotting” and ore veins evidence, in particular the observation that ore veins cut through rocks exhibiting chlorite spots, they are considered to have resulted from two separate events (Jambor, 1971c and Andrews et al., 1986).
Character and Distribution of Ore Veins
The veins occur in a variety of rock types, Huronian sediments, mainly Coleman member, Nipissing diabase, and Archean metavolcanics and metasediments. Ore veins have also been found in Archean granites and late lamprophyre dikes. The ore veins vary in width from a few inches to over 12 inches with an average width of less than 2 inches. The veins may be over 1,000 feet long and 300 feet deep and can swell and vary in width over their length. Mineralization is typically discontinuous along any given vein. The veins occur in local shear zones, along faults and zones of dilation mainly as discrete and narrow fissure fillings and rarely as a network of multiple veins which can branch and join together both along their length and depth.
Origin and Processes of Mineralization
Many of the various models on the origin of the silver veins are based on the occurrence and distribution of the silver veins. All of the deposits occur at or near the Archean-Huronian uncomformity. They are spatially associated with Nipissing diabase either within or within 600 feet of its upper and lower contacts. Many of the mineralized veins occur on the upward projection of Archean supracrustal rocks and many are found near volcanogenic base metal sulfide deposits in the Archean basement (Andrews et al., 1986).
The origin of the silver-bearing veins and their metal sources has been hotly debated since their discovery in 1903. In spite of the work done, including an entire volume of the Canadian Mineralogist (“The Silver-Arsenide Deposits of the Cobalt-Gowganda Region, Ontario”) and papers included in the Canadian Journal of Earth Sciences (vol. 23, No. 10, 1988, “Silver Vein Deposits”) the source, timing and processes of silver-arsenide vein mineralization remain unresolved.
Based on the above observations virtually every rock type that occurs in the area has been proposed as a possible source of the metals and gangue vein material. These include;
1. Archean metasedimentary beds with minor contributions from metavolcanics (Boyle and Dass, 1971; Smyk and Watkinson, 1990).
2. Archean carbonaceous, pyritic tuffs (Watkinson, 1986).
3. Base metal sulfide mounds in the Archean metavolcanics (Goodz et al., 1986).
4. Huronian sediments (Kerrich et al., 1986) and Cobalt Group sediments in particular, the Coleman member (Appleyard, 1980; Innes and Colvine, 1979).
5. Nipissing diabase (Jambor, 1971d).
6. The same magma chamber as the Nipissing diabase (Sampson and Hriskevich, 1957).
7. A separate deep rooted parental magma source (Miller, 1913; Bastin, 1939; Moore 1955).
Although it is beyond the scope of this article to present all the models that have been proposed, interested readers should refer to the references for further details, it is interesting to note that one of the earliest, most persistent and simplest models is that related to the intrusions of Nipissing diabase. In this model the diabase acted as a heat source which initiated a long term hydrothermal convection system resulting in the leaching of metals from the host rocks and their deposition in favorable faults, shear zones and zones of dilatancy. There are several lines of evidence that dispute this model; the observation that veins can cut completely across intrusions of diabase including the contact metamorphic “chlorite spots” (Andrews et al., 1986). Nipissing diabase intrusions are widely distributed throughout the Southern Province but the veins are restricted to the northern and eastern boundary of the Cobalt Embayment. Also the silver-arsenide veins at Cobalt are not unique, they are similar to other epigenetic, hydrothermal five-element (Co-Ni-As-Ag-Bi) vein assemblages found in a number of localities and the spatial association evident at Cobalt with diabase is not typical (Bastin, 1939).
Europeans have been exploring and engaged in trade, in this part of Canada, for several hundred years. In fact, the Ottawa River, Lake Temiskaming and Montreal River, all of which are in close proximity to the silver deposits, were travelled for centuries by aboriginals and Europeans with no in-situ veins ever being discovered, as far as we know. This is surprising since, for centuries, regular canoe, boat and steamer transport travelled within one km of some of the silver veins!
Recent research on silver artifacts from aboriginal cultures (Spencer and Fryer, 1990) indicates that aboriginal people DID know about silver from the Cobalt area to some extent. Trace element analyses show that silver in some artifacts ( pan pipes, buttons and jewelry) did originate from the Cobalt area and were transported/traded as far from Cobalt as Mississippi, USA. Although there were no known pre-European mine workings in the Cobalt area, it is possible that such workings were destroyed or that silver from the artifacts was gleaned from glacial drift or river washed deposits.
The French had heard rumours of silver in the region since the early days of colonization in North America. Jacques Cartier records some of these rumours in the notes from his voyage of 1535-36AD, but apparently never followed up.
Sieur de Troyes was told about an argentiferous galena vein on the eastern shore of Lake Temiskaming and investigated it on his way to James Bay in 1686. (Smith, 1986). The vein was mostly just galena and was not exploited, to any great extent, at the time. The vein did eventually become the Wright Mine and a few tons of mineralization were mined in 1850 for the lead content.
The modern discovery of silver veins at “Long Lake” coincided with the construction of the railway from North Bay to New Liskeard, to serve the growing agricultural community, in the “clay belt” north of New Liskeard. People had been settling the area north of Haileybury and New Liskeard for many years prior to the discoveries at “Long Lake”. Workers encountered heavy, metallic minerals in the vicinity of the right of way and eventually staked claims.
The most famous of these discoveries was by Fred LaRose, a blacksmith working on the railway. As legend has it, during the summer of 1903, Fred threw a hammer at a pesky fox that lingered near his forge. Apparently the hammer glanced off a rock outcrop and Fred noticed that the rock had a distinct metallic gleam to it where the hammer had hit. He collected some samples and took them with him to Haileybury on an excursion to the Matabanick Hotel, one of the favourite watering holes of people in the Haileybury area. LaRose thought that the samples could be copper rich due to the coppery colour and green oxidation stains. He gave them to the proprietor of the Matabanick, Mr. Arthur Ferland, who, in turn, showed them to T.W. Gibson, Director of the Ontario Geological Survey, who also happened to be frequenting the Matabanick Hotel. Gibson recognized that the samples contained nickel and then forwarded the samples to Dr. Willet Green Miller, the first Provincial Geologist of Ontario, accompanied by a letter which stated:
"I am enclosing herewith a fragment of a larger sample of what I take to be kupfer-nickel found along the line of the Temiskaming and Northern Ontario Railway. The locality of the deposit is in the unsurveyed territory immediately south of the Township of Bucke. I have not learned anything as to the extent of the discovery, but if the deposit is of any considerable size, it will be a valuable one on account of the high percentage of nickel which this mineral contains. I think it will almost be worth your while to pay a visit to the locality of the discovery before navigation closes. I am under the impression that the find was made while making the cutting for the railway. Mr. Ferland, of Haileybury, showed me a sample of the mineral when I was there, but he did not appear to recognize it or know its value, deeming it to be a compound of copper. It would be remarkable should our nickel deposits turn out to have a wider range than hitherto been supposed and especially if the new outcrop should be a large one containing ore of so high a grade."
Gibson was theorizing, in this note, that perhaps the nickel deposits of Sudbury, a couple of hundred km to the south-west, possibly extended up to the Lake Temiskaming area! He didn’t notice the silver in the sample!
Miller recognized that the samples were nickel-rich but also were laced with native silver! This caused him to make a visit to the Long Lake area in November of 1
