Orpiment

Formula: As2S3

Species:

Colour: Orange-yellow to lemon-yellow

Lustre: Pearly

Hardness: 1½ – 2

Specific Gravity: 3.49

Crystal System: Monoclinic

Name: From Latin “aurum”, gold, and “pigmentum”, pigment, in allusion to its color.

Isostructural with: Laphamite

May be visually similar to uzonite and wakabayashilite.