Mineralpedia Details for Copper
Origin of the name from the ancient copper mining on the island Cyprus, also called kyprios, which gave way to the Latin word cuprum, from which the elemental copper gets its chemical symbol Cu. Copper is widely distributed worldwide and can be found in large quantities in the United States, Namibia, as large crystals in Russia, Germany, as fine crystals in England, Wales, Chile, and Bolivia, among many other localities. Typically found as a hydrothermal mineral in mafic extrusives, sandstone, and shale where it formed in oxidizing conditions, as well as in oxidized, disseminated copper deposits via secondary processes, and can be found rarely in meteorites. A well known and telling property of copper is its high malleability and ductility. Copper exposed to the elements is often weathered and corroded to a green tarnish, called patina.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/copper.pdf
Copper from Keweenaw Co., Michigan, United States
Copper crystals to 9mm.
Copper from Broken Hill, New South Wales, Australia
Free-standing Copper crystal group showing spinel twinning.
Copper from Ajo, Pima Co., Arizona, United States
This specimen is an entanglement of arborescent growth Copper crystals. Each crystal is terminated nicely from elongated crystals. The matrix is partially composed of Calcite. It was said that a deficiency of Pyrite at Ajo prevented good secondary enrichment. But the upper levels were oxidized to carbonates without loss of much Copper.
Copper from Kearsarge mine, Houghton Co., Michigan, United States
Large Copper mass from amygdaloidal basalts. This specimen also contains a bit of Silver. Well over 6 million tons of native Copper has been mined from these deposits which stretch the entire length of upper Michigan from Wisconsin to Keweenaw point. The Copper occurs within open-space fillings and replacements in amygdaloidal flow tops of the Portage Lake Lava Series. These Copper deposits have been mined since prehistoric times.
Copper from White Pine mine, Ontonagon Co., Michigan, United States
Native Copper as well as thin plates of Copper along the bedding and finely disseminated Copper along bedding in black siltstone of the Nonesuch Formation which is of Upper Precambrian age. The copper deposits of the White Pine are stratifom and only moderately deformed. Two stages of mineralization have been introduced; an early Chalcocite replacement of syngenetic Pyrite and a later stage from Copper rich fluids. It is not clear to which stage these specimens belong. However, based upon the article in Rocks & Minerals (v. 74-3) by Tom Rosemeyer it is very possible it is from the first stage since the Copper occurs in thin sheets parallel to the bedding and not in the open fractures associated with the second stage.
Crystallized Copper with micro octahedral crystals with a peculiar brassy luster. Micro Bornite (?) crystals are sprinkled about the Copper.
Copper from Levant section, Geevor mine, Pendeen, St. Just, Cornwall, England
Tiny Copper crystals throughout this specimen as well as Cuprite crystals. The Levant mine is one of the most famous mines in the world having been perched high on the cliffs above the Atlantic ocean. It was a major producer of copper and tin. Mine workings reached more than a mile out beneath the sea and to a dept of 2000 feet.
Copper from Mission mine, Pima Co., Arizona, United States
Copper included within Gypsum var. Selenite as dendritic growths throughout.
Copper from Norwich, Ontonagon Co., Michigan, United States
Native Copper to 1.5cm in Epidote from presumably from the Portage Lake volcanics of the upper Michigan Lake Superior district.
Copper from Bisbee, Cochise Co., Arizona, United States
Arborescent crystals to 3cm.
Copper from Poldory Mine, Cornwall, England
Large mass of arborescent habit copper with growths to 4cm long.
Copper from Christmas mine, Gila Co., Arizona, United States
Dark tarnished Copper dendrites to 1cm.
Copper from Centennial mine, No. 2 shaft, Houghton Co., Michigan, United States
There are two large 1.5 to 2cm cubic crystals of Copper with Calcite. Most of the specimen is copper, either as crystals or as leaf/dendritic growths. An old-time specimen.
Copper from Hancock, Houghton Co., Michigan, United States
Calcite crystals from 1.5 to 2cm with included Copper. You can also see the Calcite is nestled nicely by the Copper.
Copper from Franklin, Sussex Co., New Jersey, United States
Hackly veinlets and stringers throughout green Willemite matrix.
Copper from Isle Royale mine, Houghton Co., Michigan, United States
A large hackly specimen of native Copper worked out of it's matrix of basalt and Epidote.
Copper from Centennial mine, Houghton Co., Michigan, United States
Hackly mass of Copper with conglomerate and a bit of Epidote.
Copper from Ray mine, Pinal Co., Arizona, United States
Large specimen of arborescent Copper with two plates attaached to the host rock.