orpiment

Arsenic trisulfide, As2S3, a yellow mineral used as a pigment.

Arsenic trisulphid, As2S3.

Arsenic sesquisulphide, produced artificially as an amorphous lemon-yellow powder, and occurring naturally as a yellow crystalline mineral; -- formerly called auripigment. It is used in king's yellow, in white Indian fire, and in certain technical processes, as indigo printing.

Realgar; the red sulphide of arsenic.

King's yellow.