Chalcopyrite

Chalcopyrite is a mineral composed of copper iron sulfide (CuFeS₂), considered the world's primary copper ore. It is recognized by its golden brass-yellow color and metallic luster, which can develop natural blue, purple, green, or red iridescence due to oxidation.

It often forms tetrahedral crystals or compact masses in hydrothermal deposits, usually associated with pyrite, bornite, or galena.