Chalcopyrite Chalcopyrite Chalcopyrite ( ) is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical formula CuFeS. 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 oxidises to a variety of oxides, hydroxides and sulfates. Associated copper minerals include the sulfides bornite (CuFeS), chalcocite (CuS), covellite (CuS), digenite (CuS); carbonates such as malachite and azurite, and rarely oxides such as cuprite (CuO). Chalcopyrite is rarely found in association with native copper. Natural
Volcanogenic massive sulfide ore deposit sulfidic sediments, similar to SEDEX ores, and is generally manganese, barium and hematite enriched, with cherts, jaspers and chemical sediments common. Most VMS deposits show metal zonation, caused by the changing physical and chemical environments of the circulating hydrothermal fluid. Ideally, this forms a core of massive pyrite and chalcopyrite around the throat of the vent system, with a halo of chalcopyrite-sphalerite-pyrite grading into a distal sphalerite-galena and galena-manganese and finally a chert-manganese-hematite facies. Most VMS deposits show a vertical zonation of gold, with the cooler upper portions generally more enriched in gold and silver. The mineralogy of VMS massive