Greenockite is a rare
cadmium bearing metal
sulfide mineral consisting of
cadmium sulfide (CdS) in crystalline form. Greenockite crystallizes in the
hexagonal system. It occurs as massive encrustations and as hemimorphic six-sided pyramidal crystals which vary in color from a honey yellow through shades of red to brown. The
Mohs hardness is 3 to 3.5 and the
specific gravity is 4.8 to 4.9.