FORMULA: CuFeS2
MOHS: 3.5-4
Chalcopyrite is a glittery gold mineral that sometimes oxidizes into rainbow colors. But it’s the gold version that’s been the most mystifying and probably frustrating to people over the years. Because, while you may have only heard of its more famous fool’s gold cousin, pyrite, chalcopyrite is just as tricky to prospectors and would-be millionaires.
Just like pyrite, chalcopyrite often co-occurs with gold deposits, so it’s no wonder that people have gotten confused. But it’s more useful than even those prospectors realized. Chalcopyrite is the main source of copper that we use in our pipes and wires, and several mines that were once famed for the gold they contained are now better known for the chalcopyrite, instead. Who’s the fool now?