Chalcopyrite is a copper-iron sulfide mineral that is the world's most abundant source of copper.

Chalcopyrite is often confused with pyrite and gold since all three of these minerals have a yellowish color and a metallic luster. Some important mineral characteristics that help distinguish these minerals are hardness and streak. Chalcopyrite is much softer than pyrite and can be scratched with a knife, whereas pyrite cannot be scratched by a knife. However, chalcopyrite is harder than gold, which, if pure, can be scratched by copper. Additionally, gold is malleable, while chalcopyrite is brittle. Chalcopyrite has a distinctive black streak with green flecks in it.

This particular specimen has Chalcopyrite with Galena, the darker mineral on this specimen, which happens to be lead sulfide, which can be found elsewhere in the collection.