{{Short description|Mineral}} {{Infobox mineral | name = Sarkinite | category = Arsenate minerals | boxwidth = | boxbgcolor = | image = Sarkinit-24468.JPG | imagesize = 260px | caption = | formula = Mn<sub>2</sub>(AsO<sub>4</sub>)(OH)<ref name=mindat>{{cite web|title=Sarkinite|url=http://www.mindat.org/min-3535.html|publisher=Mindat|access-date=May 28, 2012}}</ref> | IMAsymbol = Srk<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 = 8.BB.15<ref name=mindat/> | dana = 41.6.3.3<ref name=mindat/> | system = Monoclinic | class = Prismatic (2/m) <br/><small>(same H-M symbol)</small> | symmetry = ''P2m''<ref name=mindat/> | unit cell = a = 12.7795(13)&nbsp;Å <br/>b = 13.6127(14)&nbsp;Å <br/>c = 10.2188(11)&nbsp;Å <br/>β = 108.834(2)°; Z&nbsp;=&nbsp;16<ref name=mindat/> | color = Red to yellow<ref name=mindat/> | habit = Tabular<ref name=webmineral>{{cite web|title=Sarkinite|url=http://webmineral.com/data/Sarkinite.shtml|publisher=Webmineral|access-date=May 29, 2012}}</ref> or granular<ref name=mindat/> | twinning = | cleavage = Distinct on {100}<ref name=mindat/> | fracture = Irregular/Uneven, Conchoidal<ref name=mindat/> | tenacity = | mohs = 4–5<ref name=mindat/> | luster = Greasy<ref name=mindat/> | polish = | refractive = n<sub>α</sub>=1.793, n<sub>β</sub>=1.807, n<sub>γ</sub>=1.809<ref name=mindat/> | opticalprop = Biaxial (−)<ref name=mindat/> | birefringence = δ = 0.016<ref name=mindat/> | 2V = 83° (measured)<ref name=mindat/> | dispersion = r > v or r < v<ref name=mindat/> | pleochroism = Weak<ref name=mindat/> | fluorescence= | absorption = X > Z > Y<ref name=mindat/> | streak = Red to yellow<ref name=mindat/> | gravity = | density = 4.08 to 4.18 g/cm<sup>3</sup> (measured)<ref name=mindat/> | melt = | fusibility = | diagnostic = | solubility = Readily soluble in dilute acids<ref name=mindat/> | diaphaneity = Semitransparent<ref name=handbook>{{cite web|title=Sarkinite|url=http://www.handbookofmineralogy.org/pdfs/sarkinite.pdf|work=Handbook of Mineralogy|publisher=Mineral Data Publishing|access-date=May 30, 2012}}</ref> | other = | references = }} '''Sarkinite''', synonymous with '''chondrarsenite''' and '''polyarsenite''', is a mineral with formula Mn<sub>2</sub>(AsO<sub>4</sub>)(OH). The mineral is named for the Greek word ''σάρκιυος'', meaning made of flesh, for its red color and greasy luster. The mineral was first noted in Sweden in 1865 as chondrarsenite, though not identified as sarkinite until 1885.

==Description== Sarkinite is red to yellow in color. It occurs as thick tabular crystals, short prismatic crystals, or has a granular habit. Sarkinite sometimes aggregates into a roughly spherical shape. Sarkinite is a member of the Wagnerite Group.<ref name=mindat/>

The mineral occurs in manganese-rich lenses in quartzitic chlorite schists, metamorphosed zinc ore bodies, and rarely in metamorphosed Fe–Mn ore bodies.<ref name=handbook/>

==Structure== Sarkinite is isostructural with triploidite and wolfeite<ref name=mindat/> and is a dimorph of eveite.<ref name=H113>Halenius, p. 113.</ref> The crystal structure consists of MnO<sub>4</sub>(OH)<sub>2</sub> octahedra, MnO<sub>4</sub>(OH) trigonal bipyramids, and AsO<sub>4</sub> tetrahedra.<ref name=DN246>Dal Negro, p. 246.</ref>

==History== In 1885, two similar minerals were discovered in Sweden. Polyarsenite was found in Grythyttan and named by Igelström for its high arsenic content. Sarkinite was discovered in Pajsberg, Persberg, and named by A. Sjögren after the Greek word ''σάρκιυος'', meaning made of flesh, in reference to the blood-red color and greasy luster. It was considered likely that the two minerals were identical.<ref>{{Cite report |author=Smithsonian Institution |year=1886 |title=Annual Report of the Board of Regents of the Smithsonian Institution Showing the Operations, Expenditures, and Condition of the Institution to July, 1885 |url=https://books.google.com/books?id=WLYAAAAAYAAJ&pg=PA701 |publisher=Government Printing Office |page=701 }}</ref> A study in 1980 showed that polyarsenite and chondrarsenite, discovered in 1865, were in fact both sarkinite.<ref>{{cite journal|last=Dunn|first=Pete J.|title=On the composition of some sarkinites|journal=Mineralogical Magazine|date=March 1980|volume=43|issue=329|url=http://rruff.geo.arizona.edu/doclib/MinMag/Volume_43/43-329-681.pdf|access-date=May 29, 2012|page=681|doi=10.1180/minmag.1980.043.329.22|bibcode=1980MinM...43..681D|s2cid=129159875 }}</ref>

==Distribution== {{As of|2012}}, sarkinite has been found in Austria, France, Italy, Japan, Kazakhstan, Romania, Sweden, Switzerland, and the United States.<ref name=mindat/>

==Association== Sarkinite has been found in association with:<ref name=handbook/>

Harstigen mine, Sweden *Barite, bementite, brandtite, calcite, lead

Sjö mine, Sweden *Jacobsite, katoptrite, magnetite, tephroite

Ködnitz Valley, Austria *Pyroxmangite, rhodochrosite, rhodonite, spessartine, tephroite, tiragalloite

Falotta mine, Switzerland *Brandtite, braunite, grischunite, manganoan berzeliite, rhodochrosite, tilasite

Sterling Hill, New Jersey, US *Adamite, allactite, barite, brandtite, copper, euchroite, eveite, kraisslite, manganese oxides, parabrandtite, rhodochrosite, serpierite, willemite

==References== {{Reflist}}

===Bibliography=== *{{cite journal|last1=Halenius|first1=Ulf|last2=Westlund|first2=Erika|title=Manganese valency and the colour of the Mn2AsO4(OH) polymorphs eveite and sarkinite|journal=Mineralogical Magazine|date=February 1998|volume=62|issue=1|pages=113–119|url=http://www.minersoc.org/pages/Archive-MM/Volume_62/62-1-113.pdf|doi=10.1180/002646198547503|bibcode=1998MinM...62..113H|s2cid=95357747}} *{{cite journal|last1=Dal Negro|first1=A.|last2=Giuseppetti|first2=G.|last3=Pozas|first3=J. M. Martin|title=The crystal structure of sarkinite, Mn2AsO4(OH)|journal=Mineralogy and Petrology|year=1974|volume=21|issue=3–4|pages=246–260|doi=10.1007/BF01081034|bibcode = 1974MinPe..21..246D }}

==External links== {{commonscat-inline|Sarkinite}}

Category:Manganese(II) minerals Category:Arsenate minerals Category:Monoclinic minerals Category:Minerals in space group 10