4.4" Iridescent Native Copper Formation - Rocklands Copper Mine

This is a natural formation of native copper with spots of iridescence, mined from the Rocklands Copper mine in Queensland, Australia. This mine was discovered in 2006, and until 2019, was operated by CuDeco Limited. It produced a wide variety of copper minerals including azurite, bornite, chalcocite, chalcopyrite, native copper, and malachite, with some cobalt, gold, magnetite, and pyrite ore as well. This specimen is from the 2017 mineral specimen recovery operation that was carried out by UK Mining Ventures Limited.

Native copper is an uncombined form of copper that occurs as a natural mineral. Copper is one of the few metallic elements to occur in native form, although it most commonly occurs in oxidized states and mixed with other elements. Native copper was an important ore of copper in historic times and was used by prehistoric peoples.

Native copper occurs rarely as isometric cubic and octahedral crystals, but more typically as irregular masses and fracture fillings. It has a reddish, orangish, and/or brownish color on fresh surfaces, but typically is weathered and coated with a green tarnish of copper carbonate.

The mines of the Keweenaw Peninsula in Upper Michigan were major copper producers in the 19th and early 20th centuries, and are still the largest deposits of native copper in the world. Native Americans mined copper on a small scale at this and several other locations, and evidence exists of copper trading routes throughout North America among native peoples, proven by isotopic analysis. The first commercial mines in the Keweenaw Peninsula (which is nicknamed the "Copper Country" and "Copper Island") opened in the 1840s.
Copper (Cu)
Rocklands Copper Mine, Cloncurry, Queensland, Australia
4.4 x 2.3"