{{Short description|Inosilicate mineral}} {{Infobox mineral | name = Xonotlite | boxbgcolor = #f5e4b5 | image = Xonotlite-Inesite-21179.jpg | caption = Combination piece with radial fibrous inesite and xonotlite | category = Inosilicates | formula = {{chem2|Ca6Si6O17(OH)2}} | IMAsymbol = Xon<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> | strunz = 9.DG.35 | dana = 66.3.1.1 | system = Monoclinic | class = Prismatic (2/''m'') <br/><small>(same H-M symbol)</small> | symmetry = ''P2/a'' | unit cell = 879.33 | color = White, grey, pale pink, lemon white, colorless | cleavage = Perfect, Good | fracture = Splintery, tough | mohs = 6.5 | luster = Vitreous, silky, pearly | streak = White | diaphaneity = Transparent, translucent | gravity = 2.70 – 2.72 | density = Measured: 2.70 – 2.72 <br />Calculated: 2.71 | opticalprop = Biaxial (+) | refractive = ''n''<sub>α</sub> = 1.583 ''n''<sub>β</sub> = 1.585 ''n''<sub>γ</sub> = 1.595 | birefringence = 0.012 | 2V = 50° | fluorescence = Short UV = weak gray-white <br />Long UV = weak white | impurities = Fe, Mn, H<sub>2</sub>O }}

'''Xonotlite''', or '''eakleite''', is a mineral of general formula {{chem2|Ca6Si6O17(OH)2}} named by the German mineralogist Karl Friedrich August Rammelsberg in 1866. The name originates from its discovery locality, Tetela de Xonotla, Puebla, Mexico. Although it was discovered in 1866, it was first described in 1959. It is approved by the IMA, but it is a grandfathered species, meaning the name supposedly represents a valid species til this day.<ref name=":0">{{Cite web|title=Xonotlite|url=https://www.mindat.org/min-4343.html|access-date=2021-11-08|website=www.mindat.org}}</ref>

== Properties == Xonotlite is an ino-silicate with double dreier chains, of which several polytypes are known. The known polytypes are Ma2bc, Ma2b2c and M2a2bc. It is a mineral related to the tobermorite group. It can be colorless, gray, light gray, lemon white, or pink. It is transparent with a vitreous to silky luster. It leaves a white streak. Xonotlite is rated 6.5 on the Mohs scale of hardness. It crystallizes in the monoclinic – prismatic crystal system,<ref name=":0" /> with typically an acicular crystal form or habit, meaning it occurs as needle-like crystals. It is massive, meaning individual crystals are hard to tell apart as they form large masses. It mainly consists of oxygen (42.52%), calcium (33.63%) and silicon (23.57%), and includes hydrogen (0.28%). It is a luminescent mineral, under short ultraviolet light it has a weak gray-white fluorescence, and under long UV it is weak white. It is not a magnetic mineral, and is not radioactive.<ref name=":1">{{Cite web|title=Xonotlite Mineral Data|url=https://webmineral.com/data/Xonotlite.shtml#.YYlE3prMKHs|access-date=2021-11-08|website=webmineral.com}}</ref>

== Environment and mining == [[Image:Xonotlite - Vicenza, Italia.jpg|thumb|left|Xonotlite from Italy]] It occurs as veins in serpentinite and contact metamorphism aureoles.<ref name=":1" /> Associated minerals include apophyllite, diopside, stilbite, tobermorite, clinohedrite, thaumasite, laumontite and wollastonite.<ref>{{Cite journal|year=2001|title=Xonotlite|url=https://rruff.info/doclib/hom/xonotlite.pdf|journal=Mineral Data Publishing}}</ref> The most common impurities include iron, magnesium and carbon dioxyde ({{CO2}}) impurities. It has many type localities, the most notable one being Tetela de Ocampo, Mexico.<ref name=":0" />

== See also == * {{annotated link|Gyrolite}} * {{annotated link|Tacharanite}} * {{annotated link|Tobermorite}}

== References == {{Reflist}}

== Further reading == * {{cite journal | last1 = Taylor | first1 = H. F. W. | title = The transformation of tobermorite into xonotlite | journal = Mineralogical Magazine and Journal of the Mineralogical Society | date = June 1959 | volume = 32 | issue = 245 | pages = 110–116 | issn = 0369-0148 | eissn = 2515-821X | doi = 10.1180/minmag.1959.32.245.03 | pmid = | bibcode = 1959MinM...32..110T | url = }}

== External links == {{Commons category|Xonotlite}} * [http://webmineral.com/data/Xonotlite.shtml Webmineral data] * [http://rruff.geo.arizona.edu/doclib/hom/xonotlite.pdf Mineral Data Publishing] {{Webarchive|url=https://web.archive.org/web/20100628102000/http://rruff.geo.arizona.edu/doclib/hom/xonotlite.pdf |date=2010-06-28 }} * [http://www.mindat.org/min-4343.html Mindat with location data]

Category:Calcium minerals Category:Inosilicates Category:Monoclinic minerals Category:Minerals in space group 13

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