Arsenic sulfide's applications

As2S3 occurs both in crystalline and amorphous forms. 

Arsenic Trisulfide is an odorless, yellow or orange, crystalline powder. Both forms feature polymeric structures consisting of trigonal pyramidal As(III) centres linked by sulfide centres. The sulfide centres are two-fold coordinated to two arsenic atoms. In the crystalline form, the compound adopts a ruffled sheet structure. The bonding between the sheets consists of van der Waals forces. The crystalline form is usually found in geological samples. 

Amorphous As2S3 does not possess a layered structure but is more highly cross-linked. Like other glasses, there is no medium or long-range order, but the first co-ordination sphere is well defined. As2S3 is a good glass former and exhibits a wide glass-forming region in its phase diagram.

The role of arsenic sulfide

It is used in the manufacture of glass, oil cloth, linoleum, electrical semi-conductors, photoconductors, and fireworks, as a pigment, and in tanning and pesticides.