Pharmacosiderite
Mineral KFe4(AsO4)3(OH)4·6-7H2O
Also called Cube ore
Take care.
- Contains arsenic: Wash your hands after handling it, don't make dust, and never heat it.
About it
Small sharp cubes in green to honey-brown, an unusual shape for an arsenate, in oxidized ore with arsenopyrite. A classic from Cornwall; also fine from Tsumeb in Namibia.
- Type
- Mineral
- Group
- Arsenate, pharmacosiderite group
- Formula
- KFe4(AsO4)3(OH)4·6-7H2O
- Hardness (Mohs)
- 2.5
- Specific gravity
- 2.79–2.8
- Streak
- pale green to pale yellow
- Lustre
- adamantine (diamond-like), greasy
- Crystal system
- Isometric (cubic)
- Colours
- olive green, yellowish green, honey yellow, brown, red
- Transparency
- transparent, translucent
- Cleavage and fracture
- poor cubic
Typical values: real specimens vary. For more, see mindat.org.