David K. Joyce

Copper, Keweenaw Peninsula, Michigan, USA

The Keweenaw Peninsula of the upper peninsula of Michigan State was one of the premier producers of copper. Not on;y were astounding tonnages of copper produced but many fantastic specimens of native copper, sometimes crystallized, were produced. The mines of the Keweenaw Peninsula were mostly underground mines that tapped either humongous deposits of copper in conglomerate/basalt strata or large fissure veins. The fissure veins were the source of most of the crystallized copper specimens that you see. The conglomerate and basalt were the source of amygdaloidal copper, Copper "skulls", and sheet copper. The geology, mineralogy and history of the "Michigan Copper Country" is fascinating and you can learn more about it in the special "Michigan Copper" issues of "Rocks and Minerals", Volume 77, No.6 or The Mineralogical Record Volume 23, No. 2. Each a fantastic publication.

All prices in Canadian dollars. For payment in US$, deduct 19% or multiply by 0.81.

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

CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #12339
  • Copper
  • 8.2x5.0x4.0 cm
  • Largest Crystal Size: n/a
  • $30.00
  • Ontonagan Co.
  • Keweenaw Peninsula
    Michigan, USA
  • A sculptural specimen of copper with quartz crystals embedded in it , mostly on the bottom. Heavy!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #11837
  • Copper
  • 4.1x3.2x1.7 cm
  • Largest Crystal Size: 10mm
  • $75.00
  • Phoenix Mine
  • Keweenaw Co.
    Michigan, USA
  • Nice parallel-growth group of copper crystals with some quartz attached. Looks great!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #11834
  • Copper
  • 5.4x5.2x4.2 cm
  • Largest Crystal Size: 28mm
  • $50.00
  • Wolverine Mine
  • Houghton Co
    Michigan, USA
  • A very sculptural group of copper crystals protrudes from a calcite vein on the side of amygdalodal basalt. Nice looking specimen! Classic.
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #11832
  • Copper
  • 3.9x1.8x1.0 cm
  • Largest Crystal Size: 42mm
  • $35.00
  • Phoenix Mine
  • Keweenaw Co.
    Michigan, USA
  • A group of copper crystal composed of a long, curved crystals and a couple of parallel growth crystals. Nice looking specimen!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #11830
  • Copper
  • 5.3x2.0x0.8 cm
  • Largest Crystal Size: 40mm
  • $60.00
  • Phoenix Mine
  • Keweenaw Co.
    Michigan, USA
  • This specimen shows one long copper crystal with a number of blockier crystals attached to one end. Great shape! Great example of copper crystals.
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #11824
  • Copper
  • 3.5x1.4x1.3 cm
  • Largest Crystal Size: 20mm
  • $40.00
  • Phoenix Mine
  • Keweenaw Co.
    Michigan, U.S.A.
  • I think this could be one elongated, full crystal of copper with some off-shooting twinned crystsals. A little calcite attached. Classic!
Copper/SilverCopper, Keweenaw Peninsula, Michigan, USA
  • Item #11823
  • Copper/Silver
  • 2.2x1.7x0.8 cm
  • Largest Crystal Size: n/a
  • $35.00
  • Osceola Mine
  • Houghton Co
    Michigan, USA
  • A cute little "nugget" of copper with an imiscible phase of silver. Excellent example!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #12356
  • Copper
  • 3.7x4.2x2.3 cm
  • Largest Crystal Size: 26mm
  • $35.00
  • Keweenaw Peninsula

  • Michigan, USA
  • This specimen sports a bright, elongated, twinned crystal of copper protruding from basalt matrix. Looks great!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #10197
  • Copper
  • 9.9x2.4x0.6 cm
  • Largest Crystal Size: 6mm
  • $30.00
  • White Pine Mine
  • Ontonagon County
    Michigan, USA
  • A spindly, dendritic cluster of distorted crystals. Interesting specimen!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #10204
  • Copper
  • 4.1x2.2x1.4 cm
  • $100.00
  • Quincy Mine
  • Houghton Co.
    Michigan, USA
  • Very nice specimen of almost solid copper made up of dendritic, elongated cube-octahedra. Classic locality!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #10224
  • Copper
  • 4.3x4.2x0.7 cm
  • Largest Crystal Size: 22mm
  • $40.00
  • Keweenaw Peninsula

  • Michigan, USA
  • A group of largish, semi-dendritic copper crystals with a partial very thin veneer of cuprite giving it a reddish tinge. Looks greaT!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #10225
  • Copper
  • 8.7x2.7x0.3 cm
  • Largest Crystal Size: 73mm
  • $25.00
  • Keweenaw Peninsula

  • Michigan, USA
  • I think that this is pretty-well one very long, distorted crystal ocopper! Very cool!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #10214
  • Copper
  • 4.3x1.2x0.6 cm
  • Largest Crystal Size: 5mm
  • $30.00
  • White Pine Mine
  • Ontonagon County
    Michigan, USA
  • This dendritic cluster of copper crystals is a fine sexample of "native copper" from the Keweenaw peninsula.
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #10240
  • Copper
  • 12.8x4.3x2.2 cm
  • Largest Crystal Size: 12mm
  • $175.00
  • Central Mine
  • Keweenaw County
    Michigan, USA
  • An excellent, old-time cluster of copper crystals from a classic locality. The specimen consists of a main branch, composed of enmeshed crystals, with a kind of divergent cluster of crystals on the end. Hard to dind specimens like this, these days. Looks great!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #10248
  • Copper
  • 10.3x3.0x2.5 cm
  • Largest Crystal Size: 85mm
  • $225.00
  • Keweenaw Peninsula

  • Michigan, USA
  • A classic keweenaw copper crystal specimen consisting ofone large distorted crystal with some smaller crystals attached. Classic! Displays well.
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #10250
  • Copper
  • 6.2x5.2x1.7 cm
  • Largest Crystal Size: 34mm
  • $225.00
  • Keweenaw Peninsula

  • Michigan, USA
  • A nice looking cluster of copper crystals with one large crystal sticking up out of the rest. Good looking piece of distorted copper crystals from this famous copper mining area. Displays well!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #12221
  • Copper
  • 6.8x4.9x1.9 cm
  • Largest Crystal Size: 32mm
  • $85.00
  • Keweenaw Peninsula

  • Michigan, USA
  • A cluster of several large, elongated crystals of copper. The crystals appear to be distorted dodecahedra and have sharp cubic crystal overgrowths on many of the crystal faces. Nice!
Copper, PrehniteCopper, Keweenaw Peninsula, Michigan, USA
  • Item #11976
  • Copper, Prehnite
  • 8.4x5.2x5.4 cm
  • Largest Crystal Size: 25mm wires
  • $225.00
  • Champion Mine
  • Houghton Co.
    Michigan, USA
  • Here is a super specimen of native copper. This specimen shows a vug in prehnite and quartz, with some of the calcite etched away that reveals excellent wires of copper. Displays perfectly!
Copper, SilverCopper, Keweenaw Peninsula, Michigan, USA
  • Item #15066
  • Copper, Silver
  • 9.0x3.3x0.9 cm
  • Largest Crystal Size: n/a
  • $45.00
  • White Pine Mine
  • Ontanagan Co.
    Michigan, USA
  • This oblong shaped glob of native copper is laced with native silver, particularly at on end. A classic "half-breed" nugget in the parlance of the Upper Peninsula copper country.
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #19111
  • Copper
  • 9.7x2.1x0.7 cm
  • Largest Crystal Size: as above
  • $250.00
  • White Pine Mine
  • Ontonagon County
    Michigan, USA
  • This piece is essentially one large, elongated crystal with some smaller crystals attached to one end. Classic Keweenaw Peninsula crystallized copper specimen at a great price!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #17430
  • Copper
  • 6.4x2.6x1.2 cm
  • Largest Crystal Size: 14mm
  • $80.00
  • Keweenaw Peninsula
    Michigan, USA
  • This is a really nice copper specimen showing fairly well-formed copper crystals in a branching, solid copper aggregate. Too bad we don't know the exact locality. Displays very well!!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #20207
  • Copper
  • 18.3x6.8x3.4 cm
  • Largest Crystal Size: as above
  • $325.00
  • White Pine Mine
  • Ontonagon County
    Michigan, USA
  • An excellent aggregate of copper crystals, associated with carbonate and zeolites, from THE last native copper mine that operated in northern Michigan. I think it closed most recently in the 1990's. Here is a large specimen from that famous operation!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #20306
  • Copper
  • 14.5x4.5x0.3 cm
  • Largest Crystal Size: 25mm
  • $65.00
  • Keweenaw Peninsula

  • Michigan, USA
  • although made up of 25mm or so crystals of copper, this is really one big, dendritic, branching crystal of native copper. Classic!
Copper, CalciteCopper, Keweenaw Peninsula, Michigan, USA
  • Item #20936
  • Copper, Calcite
  • 11.5x7.8x5.5 cm
  • Largest Crystal Size: as above
  • $140.00
  • Keweenaw Peninsula

  • Michigan, USA
  • A hackly mass of native copper with some openings showing whole calcite crystals, calcite crystal impressions and copper crystal faces. Such great specimens!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21111
  • Copper
  • 23.4x17.5x3.5 cm
  • Largest Crystal Size: 25mm
  • $425.00
  • Keweenaw Peninsula

  • Michigan, USA
  • A rather large plate of solid native copper with a green oxide patina. The plate is mostly composed of copper crystals, some large (up to 25mm) and very sharp! Very impressive piece, indicative of the nature of the copper deposits in the Keweenaw Peninsula many years ago. Extra postage required here! Impressive looking!
Datolite, CupriteCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21227
  • Datolite, Cuprite
  • 6.9x5.5x5.5 cm
  • Largest Crystal Size: n/a
  • $85.00
  • Caledonia Mine
  • Ontonagan County
    Michigan, USA
  • Here is a habit of datolite that is unique to the Keweenaw Peninsula. It is a nodule of porcelainous datolite that is speckled microscopically with small dots of cuprite or hematite. Hard to say and I have not had it tested. Very nice specimen!! Displays very well.
Copper, AnalcimeCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21300
  • Copper, Analcime
  • 13.2x10.0x4.2 cm
  • Largest Crystal Size: anal-5mm, cop-20mm
  • $375.00
  • Keweenaw Peninsula

  • Michigan, USA
  • Here is an old timer! The top of this specimen is lined with white analcime crystals which in turn have fairly sharp copper crystals clustered on the analcime. The analcime crystals are fairly lustrous trapezohedra that are hematite tinted on the right side of the piece. The copper crystals range from fairly equant isometric crystal combinations to more elongated crystals tending towards dendritic. Accompanying labels indicate that it is ex-Charles Noll collection at Marquette University. Charles Noll label included. LOOKS like an old timer. A well-known association but not one we see all that often. Displays very well!
Silver, CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21320
  • Silver, Copper
  • 7.5x4.3x4.0 cm
  • Largest Crystal Size: 9mm
  • $220.00
  • Copper Falls Mine
  • Keweenaw County
    Michigan, USA
  • A prong of silver crystals, with a couple of copper crystals attached, pokes out of a vein matrix of calcite and very light green prehnite. Some calcite has been removed to reveal fresh silver metal while the older exposed crystals have a black patina. Stands perfectly for display!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21421
  • Copper
  • 16.5x4.5x1.9 cm
  • Largest Crystal Size: 55mm
  • $85.00
  • Central Mine
  • Keweenaw County
    Michigan, USA
  • A huge, rough copper crystal is attached to the end of a rough, hackly mass of copper and crystals on this piece. Impressive! THAT is a big, blocky crystal!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21422
  • Copper
  • 6.4x4.4x5.4 cm
  • Largest Crystal Size: 10mm
  • $275.00
  • Central Mine
  • Keweenaw County
    Michigan, USA
  • Calcite has been carefully removed from around this copper to reveal beautiful, metallic-red, dendritic, copper crystals, in excellent branching aggregates. Superb example of this native element from the legendary Keweenaw Peninsula, Michigan.
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21424
  • Copper
  • 12.5x8.0x1.4 cm
  • Largest Crystal Size: 12mm
  • $120.00
  • Central Mine
  • Keweenaw County
    Michigan, USA
  • Here is an interesting one! It is largely a plate of copper encrusted with a light greenish silicate mineral(s). Interestingly, there are several fairly sharp copper crystals poking through the silicate, here and there, on both sides. Nice crystals!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21425
  • Copper
  • 5.4x3.8x2.9 cm
  • Largest Crystal Size: 20mm
  • $260.00
  • Central Mine
  • Keweenaw County
    Michigan, USA
  • A very nice, dendritic copper specimen, reflecting the "herringbone" habit that we see in copper sometimes. Crystals are sharp and in parallel growths typical of this habit. Nice example!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21426
  • Copper
  • 11.5x5.7x2.5 cm
  • Largest Crystal Size: 16mm
  • $75.00
  • Central Mine
  • Keweenaw County
    Michigan, USA
  • These copper crystals formed in a fracture and so both sides of the piece conformed to the fracture contours. Excellent crystal faces formed in the void of the fracture and these can be seen along the edge of the specimen. Classic from a classic copper mining area!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #21427
  • Copper
  • 12.5x6.0x1.0 cm
  • Largest Crystal Size: 6mm
  • $225.00
  • White Pine Mine
  • Ontonagon County
    Michigan, USA
  • An excellent example of dendritic copper crystallization from the White Pine Mine. The crystals have formed branching, twinned chains of crystals in textbook dendritic habit. In addition, they have an interesting lighter-metallic colouration and luster that gives them a unique appearance. Classic Michigan!