David K. Joyce Minerals

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!
Copper, PrehniteCopper, Keweenaw Peninsula, Michigan, USA
  • Item #19084
  • Copper, Prehnite
  • 6.4x3.5x3.2 cm
  • Largest Crystal Size: 3mm
  • $75.00
  • Caledonia Mine
  • Ontonagon County
    Michigan, USA
  • The basalt matrix in this specimen has a cavity across the front of it that is lined with light green, botryoidal prehnite and peppered with small, sharp crystals of native copper. Attractive and interesting specimen from this prolific native copper producing area. .
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 #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 #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!
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #18118
  • Copper
  • 19.2x13x1 cm
  • Largest Crystal Size: n/a
  • $110.00
  • White Pine Mine
  • White Pine, Ontonagon co.
    Michigan, USA
  • A large sheet of native copper from this famous locality. Small bits of black shale are attached here and there. The piece has been verithaned to maintain its coppery colour and luster. Looks great for display!
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!!
Copper, PrehniteCopper, Keweenaw Peninsula, Michigan, USA
  • Item #20116
  • Copper, Prehnite
  • 12.2x9.0x8.1 cm
  • Largest Crystal Size: 13mm
  • $325.00
  • Osceola Mine
  • Houghton Co.
    Michigan, USA
  • A gorgeous, well shaped copper crystal is nestled amongst botryoidal, light green prehnite, in a deep vug, in this specimen. Some smaller copper crystals scattered here and there. Beautiful cabinet specimen.
CopperCopper, Keweenaw Peninsula, Michigan, USA
  • Item #20204
  • Copper
  • 6.3x3.6x2.1 cm
  • Largest Crystal Size: as above
  • $75.00
  • Central Mine
  • Keweenaw County
    Michigan, USA
  • A cluster of elongated copper crystals from this famous old mine on the Keweenaw Peninsula. Sweet!