Copper

In nature, copper is found in the Earth's crust, 70 ppm, in metal form and in minerals such as chalcopyrite, chalcosite, bornite, tetrahedrite, enargite and antlerite [7]. Primary hydrothermal copper is mainly related to basic igneous rocks and as a product of supergene cementation. Otherwise copper is found in various minerals and metals [4]. In nature, copper is also found in sea water, 0.001-0.002 ppm [7]. The isotopes found in nature are ⁶³Cu (69.09 %, stable) and ⁶⁵Cu (30.91 %, stable) [7].

In pure solid form, copper exist in a face-centered cubic structure [7].

Notable occurrences
Keweenaw Peninsular, Lake Superior, USA (largest deposit of primaru copper); Tsumeb, Namibia and Chessy, France, Ural mountains, Russia [4]

Associated minerals
Silver, calcite, malachite, chalcosite, bornite and other secondary copper minerals [4].