Difference between revisions of "Antigorite"

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== Description ==
 
== Description ==
  
A variety of [[serpentine|serpentine]] named after the community of Antigorio in Italy. Antigorite was was first described and named for a specimen from the Antigorio valley in the Novara province of Italy.
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A variety of [[serpentine|serpentine]] named after the community of Antigorio in Italy. Antigorite was was first described and named for a specimen from the Antigorio valley in the Novara province of Italy.  It is usually dark green but may also be white, yellowish, gray, brown or black.  The translucent stones are commonly used as a gemstone in jewelry and carvings.
  
 
== Synonyms and Related Terms ==
 
== Synonyms and Related Terms ==
  
serpentine; antigorita (Esp.); antigorite (Port.); Antigorit (Deut.); antigoriet (Ned.)
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serpentine; antigorita (Esp.); antigorite (Port.); Antigorit (Deut.); antigoriet (Ned.); bowenite; williamsite; antigolite
 +
[[[SliderGallery rightalign|Antigorite.TIF~FTIR (MFA)|antigoliteRS.jpg~Raman (RASMIN)]]]
  
[[[SliderGallery rightalign|antigoliteRS.jpg~Raman|Antigorite.jpg~FTIR]]]
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== Physical and Chemical Properties ==
  
== Other Properties ==
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* Monoclinic, crystals rare, usually massive
 
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* Cleavage = perfect 
Monoclinic
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* Fracture = conchoidal
 +
* Luster = vitreous, greasy 
 +
* Streak = greenish-white
 +
* Low birefringence
 +
* May be translucent to opaque
 +
* Translucent stones may show black inclusions, white veining, or moss-like shapes
  
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
 
! scope="row"| Composition
 
! scope="row"| Composition
| Mg3Si2O5(OH)4
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| (Mg,Fe2+)3Si2O5(OH)4
 
|-
 
|-
 
! scope="row"| Mohs Hardness
 
! scope="row"| Mohs Hardness
| 3 - 5
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| 3.5 - 4.0
 
|-
 
|-
 
! scope="row"| Density
 
! scope="row"| Density
| 2.5-2.6
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| 2.5-2.6 g/ml
 +
|-
 +
! scope="row"| Refractive index
 +
| 1.56-1.57
 +
|-
 +
! scope="row"| Birefringence
 +
| 0.005 - 0.006
 
|}
 
|}
  
== Authority ==
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==Resources and Citations==
 
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* Mindat.org: [https://www.mindat.org/min-260.html antigorite]
 +
* Gem Identification Lab Manual, Gemological Institute of America, 2016.
 
* Thomas Gregory, ''The Condensed Chemical Dictionary'', Reinhold Publishing, New York, 3rd ed., 1942
 
* Thomas Gregory, ''The Condensed Chemical Dictionary'', Reinhold Publishing, New York, 3rd ed., 1942
 
 
* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 702
 
* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 702
 
+
* B.Ford et al, Studies in Conservation, vol 39, pp. 57-69. for formula
* External source or communication  Comment: see B.Ford et al, Studies in Conservation, vol 39, pp. 57-69. for formula
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* Wikipedia: [https://en.wikipedia.org/wiki/Antigorite Antigorite] [Accessed Aug. 30 2005 and Dec 2022]
 
 
* Wikipedia, the free encyclopedia, at http://www.wikipedia.com  Comment: http://en.wikipedia.org/wiki/Antigorite [Accessed Aug. 30 2005]
 
  
  
  
 
[[Category:Materials database]]
 
[[Category:Materials database]]

Latest revision as of 10:16, 5 January 2023

Antigorite

Description

A variety of Serpentine named after the community of Antigorio in Italy. Antigorite was was first described and named for a specimen from the Antigorio valley in the Novara province of Italy. It is usually dark green but may also be white, yellowish, gray, brown or black. The translucent stones are commonly used as a gemstone in jewelry and carvings.

Synonyms and Related Terms

serpentine; antigorita (Esp.); antigorite (Port.); Antigorit (Deut.); antigoriet (Ned.); bowenite; williamsite; antigolite

FTIR (MFA)

Antigorite.TIF

Raman (RASMIN)

AntigoliteRS.jpg


Physical and Chemical Properties

  • Monoclinic, crystals rare, usually massive
  • Cleavage = perfect
  • Fracture = conchoidal
  • Luster = vitreous, greasy
  • Streak = greenish-white
  • Low birefringence
  • May be translucent to opaque
  • Translucent stones may show black inclusions, white veining, or moss-like shapes
Composition (Mg,Fe2+)3Si2O5(OH)4
Mohs Hardness 3.5 - 4.0
Density 2.5-2.6 g/ml
Refractive index 1.56-1.57
Birefringence 0.005 - 0.006

Resources and Citations

  • Mindat.org: antigorite
  • Gem Identification Lab Manual, Gemological Institute of America, 2016.
  • Thomas Gregory, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 3rd ed., 1942
  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 702
  • B.Ford et al, Studies in Conservation, vol 39, pp. 57-69. for formula
  • Wikipedia: Antigorite [Accessed Aug. 30 2005 and Dec 2022]