{{Short description|Lithium magnesium aluminium inosilicate mineral}} {{Infobox mineral | name = Holmquistite | category = Inosilicate | boxwidth = | boxbgcolor = | image = Holmquistite.jpg | imagesize = 260px | caption = Holmquistite from the Foote Mineral Co., Kings Mountain, North Carolina | formula = {{chem2|(Li2)(Mg3Al2)(Si8O22)(OH)2}} | IMAsymbol = Hlm<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 = | strunz = 9.DD.05 | dana = 66.1.2.9 | system = Orthorhombic | class = Dipyramidal (mmm) <br/>H-M Symbol: (2/m 2/m 2/m) | symmetry = ''Pnma'' | unit cell = | color = | habit = | twinning = | cleavage = | fracture = | tenacity = | mohs = | luster = | polish = | refractive = | opticalprop = | birefringence = | 2V = | dispersion = | pleochroism = | fluorescence= | absorption = | streak = | gravity = | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = | other = | references = }} '''Holmquistite''' is a lithium magnesium aluminium inosilicate mineral with chemical formula {{chem2|Li2(Mg,Fe^{2+})3Al2Si8O22(OH)2}}. It crystallizes in the orthorhombic crystal system as prismatic crystals up to {{convert|10|cm|abbr=on}} or as massive aggregates. It has a Mohs hardness of 5–6 and a specific gravity of 2.95 to 3.13.
Color could vary from black, dark violet to light sky blue.
It occurs as metasomatic replacements on the margins of lithium rich pegmatites.
It was first described in 1913 from an occurrence in Utö, near Stockholm, Sweden. It was named for the Swedish petrologist Per Johan Holmquist (1866–1946).<ref name=Mindat>[http://www.mindat.org/min-1923.html Mindat with location data]</ref><ref name=Webmin>[http://www.webmineral.com/data/Holmquistite.shtml Webmineral data]</ref>
==References== {{Reflist}}
Category:Inosilicates Category:Orthorhombic minerals Category:Minerals in space group 62
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