Erythrite

Name:
Erythrite
Detailed information:

M Formula:	Co3(As)4)2•8H2O
Properties:
Crimson, peach, red, pink, or pearl gray. Contains 37.5% cobalt oxide. D 2.91–2.95, Mohs hardness 1.5–2.5, mp (decomposes). Soluble in hydrochloric acid.
Occurrence:
U.S. (California, Colorado, Idaho, Nevada), Ontario.
Hazard:
Toxic by ingestion and inhalation.
Use:
Coloring glass and ceramics.