chalcopyrite

{{Infobox mineral | name = Chalcopyrite | category = Sulfide mineral | boxwidth = | boxbgcolor = | image = Chalcopyrite-199453.jpg | alt = | caption = | formula = CuFeS2 | IMAsymbol = Ccp | molweight = 183.54 g/mol | strunz = 2.CB.10a | system = Tetragonal | class = Scalenohedral (2m) H-M symbol: ( 2m) | symmetry = I2d | unit cell = a = 5.289 Å, c = 10.423 Å; Z = 4 | color = Brass yellow, may have iridescent purplish tarnish. | habit = Predominantly the disphenoid and resembles a tetrahedron, commonly massive, and sometimes botryoidal. | twinning = Penetration twins | cleavage = Indistinct on {011} | fracture = Irregular to uneven | tenacity = Brittle | mohs = 3.5–4

| luster = Metallic | refractive = | opticalprop = Opaque | birefringence = | pleochroism = | streak = Greenish black | gravity = 4.1–4.3 | melt = | fusibility = | diagnostic = | solubility = Soluble in HNO3 | diaphaneity = Opaque | other = magnetic on heating | references = }} Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. 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.