,

Bornite, also known as Peacock Ores due to various iridescent shades of blue to purple in places, is a sulfide mineral with chemical composition Cu5FeS4, which crystallizes in the orthorhombic system (pseudo-cubic). Bornite is an important copper ore mineral and occurs widely in porphyry copper deposits along with the more common chalcopyrite. Chalcopyrite and bornite are both typically replaced by chalcocite and covellite in the supergene enrichment zone of copper deposits. Bornite is also found as disseminations in mafic igneous rocks, in contact metamorphic skarn deposits, in pegmatites and in sedimentary cupriferous shales. It is important as an ore for its copper content of about 63 percent by mass. (source: Wikipedia) Photos by Michael Marcotte Return to List Back to Michael's Hobbies page Back to Michael Marcotte's HomePage