# Chesterite

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> Markdown URL: https://mediated.wiki/source/Chesterite.md
> Source: https://en.wikipedia.org/wiki/Chesterite
> Source revision: 1254874216
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{{Short description|Silicate mineral}}
{{Infobox mineral
| name          = Chesterite 
| image         = Chesterit-chains.png
| caption       = Chesterite structure
| category      = [Inosilicates](/source/Inosilicates) (multiple chains) 
| formula       = {{chem|(Mg|,Fe)|17|Si|20|O|54|(O|H)|6}}
| IMAsymbol=Chs<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref> 
| molweight     = 2,074.96 g/mol
| strunz        = 9.DF.05
| system        = [Orthorhombic](/source/Orthorhombic)
| class         = Pyramidal (mm2) <br/><small>(same [H-M symbol](/source/H-M_symbol))</small>
| symmetry      = ''A2''<sub>1</sub>ma
| unit cell     = a = 18.61&nbsp;Å, b = 45.3&nbsp;Å, <br/>c = 5.29&nbsp;Å, V = 4,459.64&nbsp;Å<sup>3</sup>; Z&nbsp;=&nbsp;4 
| color         = Colorless, pink, brown
| cleavage      = (110) perfect 
| mohs          = 2-2.5
| luster        = Silky - pearly
| refractive    = α=1.617, β=1.632, γ=1.64
| opticalprop   = Biaxial negative
| 2V            = 70°
| birefringence = δ = 0.023
| streak        = white
| gravity       = 3.23
| diaphaneity   = transparent
| pleochroism   = weak, pink-brown
| references    = <ref>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Chesterite Mineralienatlas]</ref><ref name=ralph>Ralph, Joylon and Ida, Chau. "Chesterite." http://www.mindat.org/min-997.html.</ref><ref name=mindata>"Chesterite Mineral Data." http://webmineral.com/data/Chesterite.shtml. Accessed 3 November 2010.</ref><ref name=vablen>Veblen, D.R. and Burnham, C.W. (1978) New biopyriboles from Chester, Vermont: II. The crystal chemistry of jimthompsonite, clinojimthompsonite, and Chesterite, and the amphibole-mica reaction. American Mineralogist, 63, 1053-1073.</ref>
}}
'''Chesterite''' is a rare [silicate mineral](/source/silicate_mineral) that can be compared to [amphibole](/source/amphibole)s, [mica](/source/mica)s, and [jimthompsonite](/source/jimthompsonite).<ref name=ralph/> Its chemical formula is {{chem|(Mg|,Fe)|17|Si|20|O|54|(O|H)|6}}.  Chesterite is named after [Chester, Vermont](/source/Chester%2C_Vermont), where it was first described in 1977.<ref name="Konishi">Konishi, Hiromi, Reijo, Alviola, and Buseck, Peter R. (2004) 2111 biopyribole intermediate between pyroxene and amphibole: Artifact or natural product? American Mineralogist, 89, 15-19.</ref>  The specific geologic setting within its origin is the Carleton talc quarry in Chester, Vermont.<ref name="mindata" /> 

Chesterite has an [orthorhombic](/source/orthorhombic) crystal structure, which means it has three crystallographic axes of unequal length. All of the axes are perpendicular to each other. The stacking sequence for chesterite, which is found in micas, is very similar to orthopyroxenes and orthoamphiboles.<ref name=vablen /><ref name="Wyckoff, R.W.G. 1968">Wyckoff, R.W.G. (1968) Crystal Structures (Second edition). 310-314 p. University of Arizona, Tucson, Arizona.</ref> Chesterite is an anisotropic mineral; therefore, it allows light to travel through it at different velocities when viewed at different angles.<ref name=mindata/> Chesterite is usually found in thin sheets within [ultramafic](/source/ultramafic) rocks.<ref name=mindata /> 

A [polytype](/source/polytype) of chesterite could be [anthophyllite](/source/anthophyllite), which has a similar crystal structure.<ref name="Wyckoff, R.W.G. 1968"/>  Chesterite is used for research on stacking formations and symmetry point groups that could be possible polymorphs or polysomes of the amphibole-anthophyllite groups.<ref name=vablen /> Chesterite has no direct usage, but some geologists or scientists generally classify it under the amphibole-anthophyllite group.

==References==
{{Reflist}}

Category:Inosilicates
Category:Orthorhombic minerals
Category:Minerals in space group 36

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Adapted from the Wikipedia article [Chesterite](https://en.wikipedia.org/wiki/Chesterite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Chesterite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.