Antimony trisulfide

Antimony trisulfide, Sb₂S₃ , is a sulfide mineral commonly called stibnite or antimonite. Antimony trisulfide exists as a gray/black crystalline solid (orthorombic crystals) and an amorphous red-orange powder. It turns black due to oxidation by air. Antimony trisulfide is the most important source for antimony. It is insoluble in water and melts at 550°C. The chemical symbol of antimony (Sb) is derived from stibnite.

Amorphous (red to yellow-orange) antimony trisulfide can be prepared by treating an antimony trichloride solution with hydrogen sulfide:

When melting antimony trisulfide with iron at approx. 600°C the following reaction yields elementary antimony:

Sb2S3 is used as a pigment, in pyrotechnics (glitter and fountain mixtures) and on safety matches. In combination with antimony oxides it is also used as a yellow pigment in glass and porcelain. Antimony trisulfide photoconductors are used in vidicons for CCTV.