Atacamite
Mineral Cu2Cl(OH)3
About it
Dark emerald-green prisms with an apple-green streak, formed where copper ores weather in salty, dry ground. Named for Chile's Atacama Desert; also from Burra and Moonta, South Australia.
- Type
- Mineral
- Group
- Halide, atacamite group
- Formula
- Cu2Cl(OH)3
- Hardness (Mohs)
- 3–3.5
- Specific gravity
- 3.75–3.77
- Streak
- apple green
- Lustre
- adamantine (diamond-like), vitreous (glassy)
- Crystal system
- Orthorhombic
- Colours
- bright green, emerald green, blackish green
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.