Which mineral is the main source of copper in many deposits?

Chalcopyrite is the most common copper-bearing mineral and one of the chief ores of copper. Its formula is CuFeS2, and it typically occurs in hydrothermal veins and porphyry copper deposits. Because copper is widely used in electricity, construction, and alloys, chalcopyrite has major economic importance. The mineral has a metallic luster and a brassy yellow color that can be mistaken for gold, which is why it is sometimes called fool’s gold, though pyrite is even more famous for that nickname. Copper mining from such ores has been important since ancient times.