Main index --- Minerals list --- Metal ores index Orpiment
Derivation:From "aurum pigmentum" (Latin) gold pigment
Formula: As2S3
Description: Bright yellow. If exposed to light, it tends to turn red. You can see red bits in the specimen.

Orpiment used to be used as a pigment. It is an ore of Arsenic, which is famous in detective novels as a poison! Ratsbane, used obviously to kill rats, is an Arsenic compound.

Today, Arsenic is used in semi-conductors.

Larger picture of Orpiment: