The only important use of chalcopyrite is as an ore of copper, but this single use should not be understated. Chalcopyrite has been the primary ore of copper since smelting began over five thousand years ago. Some chalcopyrite ores contain significant amounts of zinc substituting for iron. Others contain enough silver or gold that the precious metal content more than pays…

Chalcopyrite forms under a variety of conditions. Some is primary, crystallizing from melts as accessory minerals in igneous rocks. Some forms by magmatic segregation and is in the stratified rocks of a magma chamber. Some occurs in pegmatite dikes and contact metamorphic rocks. Some is disseminated through schist and gneiss. Many volcanogenic massive sulfide deposits containing chalcopyrite are known. The most significant chalcopyrite deposits…

The most obvious physical properties of chalcopyrite are its brassy yellow color, metallic luster, and high specific gravity. These give it a similar appearance to pyrite and gold. Distinguishing these minerals is easy. Gold is soft, has a yellow streak and has a much higher specific gravity. Chalcopyrite is brittle and has a greenish gray streak. Pyrite is hard enough…

Chalcopyrite is a brass-yellow mineral with a chemical composition of CuFeS2. It occurs in most sulfide mineral deposits throughout the world and has been the most important ore of copper for thousands of years. The surface of chalcopyrite loses its metallic luster and brass-yellow color upon weathering. It tarnishes to a dull, gray-green color, but in the presence of acids the tarnish…