Chalcopyrite

Chalcopyrite ( KAL-kə-PY-ryte, -⁠koh-) is a sulfide mineral composed of copper and iron, and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green-tinged black. On exposure to air, chalcopyrite tarnishes to a variety of oxides, hydroxides, and sulfates. Associated copper minerals include the sulfides bornite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), digenite (Cu9S5); carbonates such as malachite and azurite, and rarely oxides such as cuprite (Cu2O). It is rarely found in association with native copper. Chalcopyrite is a conductor of electricity. Copper can be extracted from chalcopyrite ore using various methods. The two predominant methods are pyrometallurgy and hydrometallurgy, the former being the most commercially viable.