{{Short description|Potassium sulfate mineral}} {{infobox mineral | name = Arcanite | image = Arcanite.jpg | imagesize = 260px | alt = | caption = Arcanite | category = Sulfate mineral | formula = K<sub>2</sub>SO<sub>4</sub> |IMAsymbol=Acn<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 = 7.AD.05 | dana = | system = Orthorhombic | class = Dipyramidal (mmm) <br/>H-M symbol: (2/m 2/m 2/m) | symmetry = ''Pmcn'' | unit cell = a = 5.77, b = 10.07 <br/>c = 7.48&nbsp;[Å]; Z&nbsp;=&nbsp;4 | color = White to colorless, yellow | colour = | habit = Tabular crystals, typically in crusts and coatings | twinning = Cyclic on {110} | cleavage = Good on {010} and {001} | fracture = | tenacity = | mohs = 2 | luster = Vitreous | streak = White | diaphaneity = Transparent to translucent | gravity = 2.66 | density = | polish = | opticalprop = Biaxial (+) | refractive = n<sub>α</sub> = 1.494 n<sub>β</sub> = 1.495 n<sub>γ</sub> = 1.497 | birefringence = δ = 0.004 | pleochroism = | 2V = Measured: 67° | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | references = <ref name=Mindat>[http://www.mindat.org/min-314.html Mindat.org]</ref><ref name=Webmin>[http://www.webmineral.com/data/Arcanite.shtml Webmineral data]</ref><ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/arcanite.pdf Handbook of Mineralogy]</ref> }} '''Arcanite''' is a potassium sulfate mineral with formula K<sub>2</sub>SO<sub>4</sub>.

Arcanite was first described in 1845 for an occurrence in old pine railroad ties in the Santa Ana tin mine, Trabuco Canyon, Santa Ana Mountains, Orange County, California, US.<ref name=Mindat/><ref name=HBM/> It has also been reported from hydrothermal deposits in the Cesano geothermal field, Latium, Italy; in bat guano on the Chincha Islands of Peru; and in caves in Western Australia, South Africa and Namibia.<ref name=HBM/>

Well-crystalline specimens sold as 'arcanite' are grown synthetically in places such as Poland for the decorative specimen market and are not natural minerals.<ref name=Mindat/>

==References== {{Reflist}}

Category:Sulfate minerals Category:Potassium minerals Category:Orthorhombic minerals Category:Minerals in space group 62

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