Chalcopyrite ( /ˌkælkəˈpaɪraɪt, -koʊ-/ KAL-ko-PY-ryt sulfide mineral that crystallizes in the tetragonal CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.
On exposure to air, chalcopyrite tarnishes to a variety of oxides, hydroxides, and sulfates. Associated copper minerals include the sulfides bornite (CuS), digenite and azurite (Cu2O). Is rarely found in association with native copper. Chalcopyrite is a conductor of electricity.