Sphalerite
(Zn,Fe)S: The chemical formula of sphalerite is (Zn,Fe)S; the iron content generally increases with increasing formation temperature and can reach up to 40%. The material can be considered a ternary compound between the binary endpoints ZnS and FeS with composition ZnxFe(x-1)S, where x can range from 1 (pure ZnS) to 0.6.