Chalcopyrite
![](/Images/godic/202501/06/Chalcopyrite-Quartz-2376450452.jpg")
![Brass-yellow chalcopyrite crystals below large striated pyrite cubes](/Images/godic/202501/06/Pyrite-Chalcopyrite-Sphalerite-402970452.jpg")
![The unit cell of chalcopyrite. Copper is shown in pink, iron in blue and sulfur in yellow.](/Images/godic/202501/06/Chalcopyrite-unit-cell-3D-balls0452.png")
Chalcopyrite (/ˌkælkəˈpaɪraɪt, -koʊ-/ KAL-ko-PY-ryt) is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical formula 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.