David K. Joyce

Downs Collection, International Minerals

I am pleased to offer the mineral collection of Dr. Robert T. Downs for sale, here on the website. Dr. Downs was born and raised in Canada and lived in many places across the country. Since a boy he was interested in minerals and mineralogy and has had several mineral collections over the years. Bob was a “late starter” and, after many years working on major construction projects as a supervisor and surveyor In British Columbia and the Yukon, he finally completed a degree in mathematics at the University of British Columbia, at the age of 30. Subsequently, he completed a masters degree and then a PhD in Mineralogy and Mathematics at Virginia Polytechnic. All through his life, he collected and studied minerals and was especially good at field collecting fine and interesting mineral crystal specimens. After post-doctoral studies at the Geophysical Lab in Washington, DC, he accepted a professorship at the University of Arizona, in Tucson. He has contributed much to the world of crystallography and mineralogy over the years, in the field of crystal structures, the RRUF project, supervision of dozens of masters and PhD students, as founding curator of the New Alfie Norville Gem and Mineral Museum in Tucson and in remote sensing and mineralogical analysis for extra terrestrial missions.
The Downs collection reflects his interests over the years, particularly with the Apatite Group of minerals, fluorapatite, vanadinite, mimetite, pyromorphite, etc. As well , other specimens are some very good personally collected specimens from Southern Arizona. There are a number of other pieces that just intrigued Bob for various reasons. Here are some of his mineral specimens.

This page offers various minerals from famous localities that Dr. Downs found intriguing or beautiful.

All prices in Canadian dollars. For payment in US$, deduct 18% or multiply by 0.82.

Click on any of the following thumbnails to view a larger image of the specimen.

Quartz, var. AmetrineDowns Collection, International Minerals
  • Item #27849
  • Quartz, var. Ametrine
  • 6.5x2.7x1.9 cm
  • Largest Crystal Size: as above
  • $120.00
  • Anahi Mine
  • La Gaiba, Sandoval, Santa Cruz
  • RTD An etched crystal of "ametrine, showing about one third as citrine and the rest as amethyst. I expect that this is probably a shard of a once larger crystal and reflects just a couple of the zones. Very interesting piece. Could cut several nice ametrine gems or just be enjoyed for the mineralogical curiosity that it is!
SchorlDowns Collection, International Minerals
  • Item #27858
  • Schorl
  • 6.1x6.3x4.2 cm
  • Largest Crystal Size: 45mm
  • $195.00
  • Erongo

  • Namibia
  • RTD An excellent example of this tourmaline group mineral from the area that produces some of the best. The schorl crystals on this specimen are equant, highly lustrous and pitch-black. They are doubly terminated and hemimorphic, like most tourmalines. Stands just like this for display. Beautiful example of this mineral!
Aegirine, Microcline, Parisite ps.Downs Collection, International Minerals
  • Item #27834
  • Aegirine, Microcline, Parisite ps.
  • 6.6x7.3x3.1 cm
  • Largest Crystal Size: 31mm
  • $230.00
  • Mount Malosa
  • Zomba
  • RTD A stunning cluster of pitch-black aegirine crystals associated with creamy-whitish microcline crystals. The aegirine crystals are amazingly sharp prisms with terminations that are steep pyramids. There are also some pseudomorphs on the speicmen that were parisite crystals that have been replaced by a mixture of Ce-rich rare earth minerals. Beautiful specimen! Displays very well! Way better than in the photographs.
Babingtonite, Prehnite, QuartzDowns Collection, International Minerals
  • Item #27838
  • Babingtonite, Prehnite, Quartz
  • 5.2x4.2x2.8 cm
  • Largest Crystal Size: b-17mm, p-15mm, q27mm
  • $225.00
  • Qiaojia
  • Yunnan
  • RTD A really nice miniature specimen showing a sharp, composite babingtonite crystal sitting atop a cluster of sharp, colourless quartz crystals and light green hemispheres of prehnite. The hemispheres are actually a darker green than shows in the photo. Wonderful babingtonite crystal! Great looking specimen!
Mimetite, CalciteDowns Collection, International Minerals
  • Item #27979
  • Mimetite, Calcite
  • 4.6x4.2x2.8 cm
  • Largest Crystal Size: 6mm
  • $45.00
  • Santa Eulalia
  • Aquiles Serdan, Chihuahua
  • RTD This specimen is, essentially a cavity of composite mimetite crystals. If you look carefully, the crystals are composed of, sharp, stepped pyramidal and prismatic faces but they appear botryoidal. Some white calcite crystals at the bottom of the cavity. Very nice specimen from this famous mining area!
StibniteDowns Collection, International Minerals
  • Item #27991
  • Stibnite
  • 7.8x4.7x4.6 cm
  • Largest Crystal Size: 24mm
  • $180.00
  • Baia Sprie

  • Romania
  • RTD This specimen is a cluster of stout, well terminated stibnite crystals from one of the most famous localities for this mineral. There are a couple of crystals missing but that is not very noticeable. Displays very well!
GrossularDowns Collection, International Minerals
  • Item #28013
  • Grossular
  • 3.4x2.4x2.3 cm
  • Largest Crystal Size: as above
  • $65.00
  • Sierra de Cruces
  • Coahuila
  • RTD A sharp grossular crystal showing a predominate dodecahedron, modified by thin trapezohedral faces. The crystal has an odd greenish-yellow colour and has a small area of attachment on the bottom. You have to love a crystal like this!
HematiteDowns Collection, International Minerals
  • Item #28015
  • Hematite
  • 3.4x2.3x2.7 cm
  • Largest Crystal Size: as above
  • $220.00
  • Wessels Mine
  • Hotazel, Cape Province
    South Africa
  • RTD This is a single crystal that is, actually, very difficult to photograph because of the brilliant faces. The crystals are composite, showing rhombs with many modifying faces. About as high of a luster as you can find on a hematite crystal! No damage. Was attached on the bottom and part of back. Beautiful and interesting!
Spodumene, var. KunziteDowns Collection, International Minerals
  • Item #28016
  • Spodumene, var. Kunzite
  • 5.8x3.6x1.8 cm
  • Largest Crystal Size: as above
  • $440.00
  • Mawi Pegmatite
  • Nuristan
  • RTD A gorgeous, deep-lilac coloured, singly-terminated, crystal of spodumene from the famous pegmatite area in Afghanistan. The crystal is well formed with deep stri and a smaller parallel growth crystal. As well, there is a small, parallel-growth spodumene crystal protruding from the top! Excellent termination and fairly gemmy in the interior. Excellent example!
BerylDowns Collection, International Minerals
  • Item #28017
  • Beryl
  • 3.8x1.5x1.4 cm
  • Largest Crystal Size: as above
  • $80.00
  • Minas Grais

  • Brazil
  • RTD This, fairly gemmy, singly terminated crystal of beryl, with slightly aquamarine-tinted colouration, is mostly interesting for the large tube that extends right through the crystal from top to bottom. You can see through it! Odd how beryl has the propensity to have tubes through it like this!
Epidote, PrehiniteDowns Collection, International Minerals
  • Item #28018
  • Epidote, Prehinite
  • 3.6x3.0x2.1 cm
  • Largest Crystal Size: e-35mm
  • $35.00
  • Djouga
  • Bendoukou, Kayes
  • RTD A very well formed, dark green epidote crystal atop a light green ball of prehnite crystals. The epidote is doubly terminated and an excellent example of this mineral.
Quartz, var. FadenDowns Collection, International Minerals
  • Item #28022
  • Quartz, var. Faden
  • 6.0x3.8x2.6 cm
  • Largest Crystal Size: a
  • $85.00
  • Dara Ismael Khan District
  • S. Waziristan
  • RTD Here is an excellent example of a "faden" growth of quartz. It is a certain style of growth, often seen in alpine cleft occurrences where the quartz crystals formed after relatively rapid changes to the cavity opening shape, during mountain building. You can see the faden "string" across the center of the crystal cluster. Crystallized on all sides.
Hematite, RutileDowns Collection, International Minerals
  • Item #28023
  • Hematite, Rutile
  • 6.1x3.1x2.1 cm
  • Largest Crystal Size: as above
  • $180.00
  • Itibiara
  • Bahia
  • RTD THIS is a tough one to photograph,, since it is so lustrous. I have tried to take photos that communicate the excellent forms and crystal structure of this crystal! It is simply an excellent hematite crystal but on the back there are some small , golden rutile crystals. Excellent and unique!
CalciteDowns Collection, International Minerals
  • Item #28026
  • Calcite
  • 5.5x4.2x3.2 cm
  • Largest Crystal Size: 30mm
  • $40.00
  • St. Clothilde

  • Quebec, Canada
  • RTD A cluster of sharp, disc-shaped calcite crystals from this famous quarry in Quebec. The crystals are actually largely flattened rhombohedra with small prism faces, there is a small ding on one of the crystals, as you can see. Nice cluster collected back in 1986!
EpidoteDowns Collection, International Minerals
  • Item #28028
  • Epidote
  • 4.8x3.9x4.6 cm
  • Largest Crystal Size: as above
  • $95.00
  • Quetta
  • Baluchistan
  • RTD Here is a large, blocky, well formed epidote crystal from this famous locale. The crystal is striated with smaller crystals attached to it in a couple of places. Feels great! Looks great!
QuartzDowns Collection, International Minerals
  • Item #28037
  • Quartz
  • 7.1x5.5x3.2 cm
  • Largest Crystal Size: as above
  • $120.00
  • Anahi Mine
  • Santa Cruz
  • RTD An unusually coherent, doubly terminated crystal from this famous "ametrine" locality. The crystal is unusually lustrous, very gemmy and shows mostly amethyst colouration with some areas of citrinous quartz. It is not perfect like most of the crystals from this locality but WAY better formed and preserved than most. Nice crystal!
Malachite, ps AzuriteDowns Collection, International Minerals
  • Item #28039
  • Malachite, ps Azurite
  • 3.6x3.0x2.3 cm
  • Largest Crystal Size: 36mm
  • $245.00
  • Milpillas Mine
  • Sonors
  • RTD A sharp cluster of crystals that are malachite pseudomorphs after azurite. The crystals, although, changed to malachite by geological processes, retain the shape of the azurite crystals perfectly! Excellent example!
Koettigite, GypsumDowns Collection, International Minerals
  • Item #28040
  • Koettigite, Gypsum
  • 9.0x5.4x2.6 cm
  • Largest Crystal Size: 3mm
  • $245.00
  • Ojuela Mine
  • Mapimi, Durango
  • RTD The top of this specimen is honeycombed with openings that contain a dozen and a half, or so clusters of grey-blue koettigite crystals. The Koettigite crystals are sharp, well terminated crystals. This is one of the relatively rare minerals that occurs at Ojula Mine, collected many years ago. Accompanied by a Ward's Science Establishment label. Excellent!
EpidoteDowns Collection, International Minerals
  • Item #28045
  • Epidote
  • 5.8x4.7x2.0 cm
  • Largest Crystal Size: as above
  • $75.00
  • Quetta
  • Baluchistan
  • This single, sharp crystal of epidote has a tabular crystal habit. It is lustrous all over but the lustre is partly obscured by loads of tiny, epidote crystals that partly cover most of the crystal faces. Some smaller epidote crystals are on the back of the main crystal. Really nice crystal!
Quartz, var. FadenDowns Collection, International Minerals
  • Item #28052
  • Quartz, var. Faden
  • 4.6x2.8x2.1 cm
  • Largest Crystal Size: 1mm
  • $55.00
  • Dara Ismael Khan Dist.
  • South Wariristan
  • RTD A cluster of the peculiar habit of quartz, known as a "faden". Fadens happen when quartz grains act as seed crystals on the sides of exer expanding alpine clefts, while quartz continually crystallizes on them over time. Very good example showing the faden inclusions down the middle of the quartz crystals.
CorundumDowns Collection, International Minerals
  • Item #28061
  • Corundum
  • 5.0x2.8x2.4 cm
  • Largest Crystal Size: as above
  • $75.00
  • Soutpansburg Range
  • Limpopo
    South Africa
  • RTD A well formed simple, doubly terminated, blue-grey corundum crystal from this famous corundum producing area of the world. The crystal has triangular terminal markings on one of the terminations. Excellent example!