Domeykite
Mineral Cu3As
Take care.
- Contains arsenic: Wash your hands after handling it, don't make dust, and never heat it.
About it
Tin-white copper arsenide that soon tarnishes yellow-brown and iridescent; usually massive. Named for Ignacy Domeyko; known from Chile and Michigan's Keweenaw Peninsula.
- Type
- Mineral
- Group
- Arsenide
- Formula
- Cu3As
- Hardness (Mohs)
- 3–3.5
- Specific gravity
- 7.2–7.9
- Streak
- grey to black
- Lustre
- metallic
- Crystal system
- Isometric (cubic)
- Colours
- tin white, steel grey, yellowish to iridescent tarnish
- Transparency
- opaque
- Cleavage and fracture
- none; uneven fracture
Typical values: real specimens vary. For more, see mindat.org.