As2S3Monoclinic
Orpiment
As2S3
SulfidesChemical FormulaAs2S3
Crystal SystemMonoclinic
Mohs Hardness1.5
Specific Gravity3.49
ColorYellow to orange yellow
LusterResinous to pearly
StreakPale yellow
CleavageOne direction
FractureFlexible
Occurrence
Found in hydrothermal veins. Bright yellow. Used as pigment historically. Toxic.