Apachite

{{Infobox mineral | name = Apachite | category = Silicate mineral | image = | caption = | formula = Cu₉Si₁₀O₂₉·11(H₂O) |IMAsymbol=Apa<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 = 1514.92 g/mol | strunz = 9.HE.10 | system = Monoclinic <br/>Unknown space group | symmetry = | unit cell = a = 12.89, b = 6.055 <br/>c = 19.11&nbsp;[Å], β = 90.42° <br/>V = 1,490.24&nbsp;ų; Z&nbsp;=&nbsp;2 | color = light blue | habit = spherical, rounded aggregates | twinning = | cleavage = | fracture = | tenacity = | mohs = 2 | luster = nonmetallic, silky | refractive = n_α=1.610, n_β=1.650, n_γ=1.650 | opticalprop = biaxial negative | 2V = Small | birefringence = δ = 0.040 | pleochroism = | streak = light blue | gravity = 3.37 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = translucent | other = | references = <ref name=Webmin>[http://webmineral.com/data/Apachite.shtml Webmineral data]</ref><ref name=HBM>[http://www.handbookofmineralogy.org/pdfs/apachite.pdf Handbook of Mineralogy]</ref> }} '''Apachite''' is a copper silicate mineral with a general formula of Cu₉Si₁₀O₂₉·11H₂O.<ref>American Geological Institute. [http://www.lib.utexas.edu/indexes/titles.php?let=G University of Texas Libraries] {{Webarchive|url=https://web.archive.org/web/20100610142415/http://www.lib.utexas.edu/indexes/titles.php?let=G |date=2010-06-10 }}. "Glossary of Geology." September 8, 2010</ref> The name is associated with the Apache tribe residents of the area near the Christmas copper mine in the Dripping Spring Mountains of Gila County, Arizona, the location where apachite was first described in 1980.<ref name=Mindat>[http://www.mindat.org/min-272.html Mindat.org]</ref>

Apachite has monoclinic crystal symmetry, displaying 3 axes of unequal length with two of the axes perpendicular to each other as well as one angle oriented less than 90°.<ref name=HBM/> The mineral has a maximum birefringence value of δ = 0.040 which describes the difference between the highest and lowest index of refraction for the mineral. Apachite is an anisotropic mineral, so the velocity of light varies for this mineral.

It occurs in retrograde metamorphic environment as fractures cutting garnet diopside skarn. It occurs associated with kinoite, gilalite, stringhamite, junitoite, clinohedrite, xonotlite, apophyllite, calcite and tobermorite.<ref name=HBM/>

== References == {{Reflist}}

Category:Copper(II) minerals Category:Unclassified silicates 11 Category:Monoclinic minerals Category:Minerals described in 1980

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