Chalcosiderite
Mineral CuFe3+6(PO4)4(OH)8·4H2O
About it
The iron-rich partner of turquoise, usually as bright green crusts of small glassy crystals rather than nodules. Classic specimens come from Cornwall, England.
- Type
- Mineral
- Group
- Phosphate, turquoise group
- Formula
- CuFe3+6(PO4)4(OH)8·4H2O
- Hardness (Mohs)
- 4.5
- Specific gravity
- 3.1–3.3
- Streak
- pale green
- Lustre
- vitreous (glassy)
- Crystal system
- Triclinic
- Colours
- light green, dark green, yellowish green
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction, good in another
Typical values: real specimens vary. For more, see mindat.org.