Peacock ore, chalcopyrite 1-2cm - Silver Hills 0.01kg

Peacock ore, or Chalcopyrite, pronounced kal-co-pie-right (kal as in “calendar”, “co” as in coat), is a copper iron sulfide mineral that crystallizes in the tetragonal system. The name “Chalcopyrite” is derived from the Greek words chalkos, “copper” and pyrites, “strike fire”. It is normally brass yellow but may have a purplish blue tarnish. The tarnish can produce a colorful, metallic iridescence and as a result it is often called “peacock ore.” Chalcopyrite is opaque and can be treated with acid to produce a greater tarnish. Chalcopyrite is present in volcanogenic massive sulfide ore deposits and sedimentary exhalative deposits, formed by deposition of copper during hydrothermal circulation. It is concentrated in this environment via fluid transport. Chalcopyrite is the most important copper ore, and it occurs in a variety of ore types, from huge masses as at Timmins, Ontario, to irregular veins and disseminations associated with granitic to dioritic intrusives as in the porphyry copper deposits of Broken Hill, the American cordillera and the Andes. Chalcopyrite is present in the supergiant Olympic Dam Cu-Au-U deposit in South Australia. It may also be found in coal seams associated with pyrite nodules, and as disseminations in carbonate sedimentary rocks.