Clinoclase
Mineral Cu3(AsO4)(OH)3
Take care.
- Contains arsenic: Wash your hands after handling it, don't make dust, and never heat it.
About it
Deep blue-green, nearly black crystals that show vivid blue on thin edges, in oxidized copper-arsenic ore. Classic from Cornwall and the Tintic district of Utah.
- Type
- Mineral
- Group
- Arsenate
- Formula
- Cu3(AsO4)(OH)3
- Hardness (Mohs)
- 2.5–3
- Specific gravity
- 4.33–4.38
- Streak
- bluish green
- Lustre
- vitreous (glassy), pearly
- Crystal system
- Monoclinic
- Colours
- dark greenish blue, blackish blue
- Transparency
- translucent
- Cleavage and fracture
- perfect in one direction
Typical values: real specimens vary. For more, see mindat.org.