Native copper
| Copper | ||
|---|---|---|
Specific gravity 8.95 | | |
| Solubility | Soluble in nitric acid | |
| Other characteristics | Tarnishes to black or green in air. | |
| References | [1][2][3][4] | |
Native copper is an
oxidized states and mixed with other elements. Native copper was an important ore
of copper in historic times and was used by pre-historic peoples.
Properties
Native copper occurs rarely as isometric cubic and
hardness is 2.5–3.[5]
Varieties
Depending on the amount and nature of impurities, several groups of varieties of native copper are distinguished. Here are the main ones:
- Ferrous copper (a type of copper containing up to 2.5% Fe);
- Copper aureus (a variety of copper containing up to 3% Au);
- Copper is silver (a type of copper containing up to 7.5% Ag).
Deposits and mines
The mines of the
Keweenaw native copper deposits of Upper Michigan were major copper producers in the 19th and early 20th centuries, and are the largest deposits of native copper in the world.[6] Native Americans mined copper on a small scale at this and many other locations,[7] 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. Isle Royale in western Lake Superior was also a site of many tons of native copper. Some of it was extracted by native peoples, but only one of several commercial attempts at mining turned a profit there.[6] An archived record of native copper originally found up river from Lake Superior, on the west branch of the Ontonagon River, via being dragged by a glacier is seen in the Ontonagon Boulder
now in the possession of the Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution.
Another major native copper deposit is in Coro Coro, Bolivia.
The name copper comes from the Greek kyprios, "of Cyprus", the location of copper mines since pre-historic times.[3]
Gallery
- Specimens from notable native copper localities worldwide
-
Broken Hill, New South Wales, Australia -
Native copper cementing host rock,Ray Mine, Arizona -
Itauz Mine, Kazakhstan -
Tsumeb, Namibia -
Dendritic native copper encased in transparent gypsum, Mission Mine, Pima County, Arizona, US -
"Halfbreed" copper-silver nugget, Keweenaw County, Michigan, US -
See also
- Copper Inuit – Inuit in Canada
- Native element mineral – Elements that occur in nature as minerals in uncombined form
- Noble metal – Metallic elements that are nearly chemically inert
- Gangue – Commercially worthless material that surrounds a wanted mineral in ore
- Native state (metallurgy)
References
- ^ Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Copper" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 4 July 2022.
- ^ Copper, WebMineral.com, retrieved 2009-12-04
- ^ a b Copper, Mindat.org, retrieved 2009-12-04
- ISBN 0-471-80580-7
- ^ "Native Copper". Amethyst Galleries' Mineral Gallery. Archived from the original on 2005-06-28. Retrieved 2005-06-26.
- ^ a b "Michigan's Copper Deposits and Mining". Archived from the original on 2005-09-09. Retrieved 2005-06-26. (Web archive; click cancel when it asks for authentication.)
- ISBN 9781298905062. Retrieved July 17, 2011.
Further reading
- Thurner, Arthur W. Strangers and Sojourners - A History of Michigan's Keweenaw Peninsula (Detroit, Michigan, U.S.A.: Wayne State University Press, 1994) ISBN 0-8143-2396-0.B
- "Prehistoric Copper in Wisconsin". Mississippi Valley Archaeology Center. Archived from the original on 2005-08-30. Retrieved 2005-06-26.
External links
Wikimedia Commons has media related to Native copper.