Peacock Ore - Large Chunk (2-3 inch)

This large chunk of peacock ore (Bornite), 2-3 inches in diameter, is great for any mineral collection.

Bornite is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system (pseudo-cubic). It has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places. This striking iridescence gives it the nickname peacock copper or peacock ore.  Bornite is not disimilar to chalcopyrite (both are important copper ores), but bornite bears a natural iridescence that must be artificially added to chalcopyrite.  Many samples of chalcopyrite are sold with this artificial iridescence but bornite exhibits it on principle.  Makes an excellent gift for the earth science instructor or geologist in your family.