antigorite
Sign in to saveAntigorite is a lamellated, monoclinic mineral in the phyllosilicate serpentine subgroup with the ideal chemical formula of (Mg,Fe2+)3Si2O5(OH)4. It is the high-pressure polymorph of serpentine and is commonly found in metamorphosed serpentinites. Antigorite, and its serpentine polymorphs, play an important role in subduction zone dynamics due to their relative weakness and high weight percent of water (up to 13 weight % H2O). It is named after its type locality, the Geisspfad serpentinite, Valle Antigorio in the border region of Italy/Switzerland and is commonly used as a gemstone in jewelry
Key facts
- Mineral.name
- Antigorite
- Mineral.image
- Antigorite from Poland.jpg
- Mineral.caption
- Antigorite crystals in serpentinite from Poland
- Mineral.category
- Phyllosilicate minerals
- Mineral.group
- Kaolinite-Serpentine group, serpentine subgroup
- Mineral.formula
- (Mg, Fe)3Si2O5OH4
- Mineral.IMAsymbol
- Atg
- Mineral.strunz
- 9.ED.15
- Mineral.system
- Monoclinic
- Mineral.color
- Green, yellowish-green, blueish-gray
- Mineral.habit
- Massive or platy
- Mineral.cleavage
- (001) Perfect
- Mineral.fracture
- Brittle
- Mineral.mohs
- 3.5–4
- Mineral.luster
- Vitreous to greasy
- Mineral.opticalprop
- Biaxial (−)
- Mineral.refractive
- 1.53–1.575
- Mineral.birefringence
- δ = 0.005–0.006
via Wikipedia infobox
Wikidata facts
- Image
- Antigorite-199680.jpg
Show 6 more facts
- Nickel-Strunz '10th ed', review of (9th ed/ 2009 update)
- 9.ED.15
- Nickel-Strunz 9th edition (updated 2009)
- 9.ED.15
- Commons category
- Antigorite
- IMA Mineral Symbol
- Atg
- chemical formula
- Mg₃Si₂O₅(OH)₄
- Strunz 8th edition (series ID, updated)
- VIII/E.10b
Sources (1)
via Wikidata · CC0
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Article
6 sectionsContents
- Geologic occurrences
- Physical properties
- Gemstone properties
- Crystal structure
- See also
- References
Antigorite is a lamellated, monoclinic mineral in the phyllosilicate serpentine subgroup with the ideal chemical formula of (Mg,Fe2+)3Si2O5(OH)4. It is the high-pressure polymorph of serpentine and is commonly found in metamorphosed serpentinites. Antigorite, and its serpentine polymorphs, play an important role in subduction zone dynamics due to their relative weakness and high weight percent of water (up to 13 weight % H2O). It is named after its type locality, the Geisspfad serpentinite, Valle Antigorio in the border region of Italy/Switzerland and is commonly used as a gemstone in jewelry and carvings.
== Geologic occurrences == Antigorite is found in low-temperature, high-pressure (or high-deformation) environments, including both extensional and compressional tectonic regimes. Serpentines are commonly found in the ultramafic greenschist facies of subduction zones, and are visible on the Earth's surface through secondary exhumation. Serpentinites that contain antigorite are usually highly deformed and show distinct textures, indicative of the dynamic region where they were formed. Antigorite serpentinites commonly have associated minerals of magnetite, chlorite, and carbonates. Olivine under hydrothermal action, low grade metamorphism and weathering will transform into antigorite, which is often associate with talc and carbonate. + + → + → + +