Brochantite
Mineral Cu4(SO4)(OH)6
About it
Emerald-green needles and prisms in the oxidized zones of copper deposits, often with malachite but not fizzing in acid as malachite does. Fine specimens come from Bisbee in Arizona and Chuquicamata in Chile.
- Type
- Mineral
- Group
- Sulfate, basic copper sulfate
- Formula
- Cu4(SO4)(OH)6
- Hardness (Mohs)
- 3.5–4
- Specific gravity
- 3.9–4
- Streak
- light green
- Lustre
- vitreous (glassy), pearly
- Crystal system
- Monoclinic
- Colours
- emerald green, blackish green
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction
Typical values: real specimens vary. For more, see mindat.org.