Mineral Chemistry
Sphalerite is the primary ore mineral of zinc and is extremely widespread. It may be found in hydrothermal veins, replacement deposits, as veins in igneous rocks, and in contact metamorphic deposits. Often found in association with galena (PbS), the name 'Blende' for sphalerite means blind or deceiving - resembling galena but yielding no lead.

Sphalerite almost always contains some iron substituting for zinc - up to 40 mole percent FeS may be contained in the sphalerite structure. Other elements which may be found as minor or trace elements in sphalerite include Cd, Mn, Ga, Ge, In, Co and Hg. The wurtzite polymorph has Zn and S atoms in hexagonal close packing.