chamosite
Sign in to saveAlso known as orthochamosite, clinochamosite
Chamosite is the Fe2+ end member of the chlorite group. A hydrous aluminium silicate of iron, which is produced in an environment of low-to-moderate-grade metamorphosed iron deposits, as grey or black crystals in oolitic iron ore. Like other chlorites, it is a product of the hydrothermal alteration of pyroxenes, amphiboles and biotite in igneous rock. The composition of chlorite is often related to that of the original igneous mineral, so that more Fe-rich chlorites are commonly found as replacements of the Fe-rich ferromagnesian minerals (Deer et al., 1992).
Key facts
- Mineral.name
- Chamosite
- Mineral.image
- Chamosite-359495.jpg
- Mineral.caption
- A 3.6 by 2.2 cm of Axinite-Fe covered on both sides by greenish microcrystals of Chamosite
- Mineral.category
- Phyllosilicate minerals
- Mineral.group
- Chlorite group
- Mineral.formula
- (Fe2+,Mg)5Al(AlSi3O10)(OH)8
- Mineral.IMAsymbol
- Chm
- Mineral.strunz
- 9.EC.55
- Mineral.system
- Monoclinic
- Mineral.class
- Prismatic (2/m) (same H-M symbol)
- Mineral.symmetry
- C2/m
- Mineral.unit cell
- a = 5.37 Å, b = 9.3 Å, c = 14.22 Å; β = 97.88°; Z = 2
- Mineral.color
- Green, grey-green, black
- Mineral.mohs
- 3
via Wikipedia infobox
Wikidata facts
- Image
- Chamosite-359495.jpg
Show 7 more facts
- Nickel-Strunz 9th edition (updated 2009)
- 9.EC.55
- Commons category
- Chamosite
- Nickel-Strunz '10th ed', review of (9th ed/ 2009 update)
- 9.EC.55
- Mohs' hardness
- 3
- IMA Mineral Symbol
- Chm
- chemical formula
- (Fe²⁺,Mg,Al,Fe³⁺)₆(Si,Al)₄O₁₀(OH,O)₈
- Strunz 8th edition (series ID, updated)
- VIII/E.09d
Sources (2)
via Wikidata · CC0
~5 min read
Article
7 sectionsContents
- History
- Structure
- Physical properties
- Geologic occurrence
- References
- Further reading
- External links
Chamosite is the Fe2+ end member of the chlorite group. A hydrous aluminium silicate of iron, which is produced in an environment of low-to-moderate-grade metamorphosed iron deposits, as grey or black crystals in oolitic iron ore. Like other chlorites, it is a product of the hydrothermal alteration of pyroxenes, amphiboles and biotite in igneous rock. The composition of chlorite is often related to that of the original igneous mineral, so that more Fe-rich chlorites are commonly found as replacements of the Fe-rich ferromagnesian minerals (Deer et al., 1992).
== History == In 1820, Pierre Bertier, a mineralogist and mining engineer from Nemours, France, discovered chamosite. The new mineral was found in an area of low-to-moderate-grade metamorphosed iron deposits. Early samples of chamosite (which is a chlorite) stirred some controversy after they were found to possess the structure of kaolin rather than chlorite; however, further research proved that chamosite was found in nature largely alongside another phyllosilicate called berthierine, which has a kaolin-type structure and is rather difficult to distinguish from chamosite. Chamosite is named after the municipality of Chamoson, between Sion and Martigny, in the canton of Valais, Switzerland.