Amesite
| Amesite | ||
|---|---|---|
Specific gravity 2.77 | | |
| Optical properties | Biaxial (+) | |
| Refractive index | nα = 1.597 nβ = 1.599 nγ = 1.615 | |
| Birefringence | δ = 0.018 | |
| Other characteristics | Kaolinite-serpentine group | |
| References | [2][3][4] | |
Amesite is a mineral with general formula of Mg2Al2SiO5(OH)4.[3]
Amesite crystallizes in the triclinic crystal system.[5] It contains three axes of unequal length, not at right angles.
It was first described in 1876 for an occurrence in the Chester Emery Mines, Chester, Hampden County, Massachusetts. It was named for mine owner James Ames.[4][3] It occurs in an environment of low-grade metamorphism affecting rocks with high aluminium and magnesium content. It occurs associated with vesuvianite, chlorite, magnetite, rutile, diaspore, grossular, calcite, diopside and clinozoisite in various locations.[2]
Amesite is an uncommon
polytype for a trioctahedral 1:1 layer silicate.[6]
References
- S2CID 235729616.
- ^ a b Handbook of Mineralogy
- ^ a b c d Mindat.org
- ^ a b Webmineral data
- ^ Roberts, W.L. (1974) Encyclopedia of Minerals, p. 18. Van Nostrand Reinhold Company, New York, New York.
- ^ Hall, Stephen H; Bailey, S.W. (5 January 1976). "Amesite From Antartica" (PDF). American Mineralogist. 61: 497–499. Retrieved 28 October 2022.
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