However the large quantities and widespread distribution of chalcopyrite make it the leading source of copper. Chalcopyrite is a common mineral and is found in almost all sulfide deposits. Fine crystals of chalcopyrite have a unique character and can add to anyone's collection. Color is brassy yellow, tarnishes to irredescent blues, greens, yellows and purples. Luster is metallic.
Crystals are opaque.
Crystals sometines twinned. Also commonly massive, and sometimes botryoidal. Cleavage is rather poor in one direction. Fracture is conchoidal and brittle. Streak is dark green.