Chamosite
Mineral (Fe,Mg)5Al(AlSi3O10)(OH)8
About it
Dark green iron chlorite, the main mineral of many oolitic ironstones, as at Chamoson, Switzerland; rarely seen as distinct crystals.
- Type
- Mineral
- Group
- Silicate (phyllosilicate), chlorite group
- Formula
- (Fe,Mg)5Al(AlSi3O10)(OH)8
- Hardness (Mohs)
- 2–3
- Specific gravity
- 3–3.4
- Streak
- green to grey
- Lustre
- pearly, dull
- Crystal system
- Monoclinic
- Colours
- green, greenish grey, black, brown
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- perfect in one direction
Typical values: real specimens vary. For more, see mindat.org.