{{Infobox mineral | name = Fontarnauite | boxwidth = | boxbgcolor = | image = Fontarnauita.jpg | imagesize = 260 | alt = | caption = Fontarnauite, Anatolia, West Turkey | category = Borate minerals | formula = {{chem2|(Na,K)2(Sr,Ca)(SO4)[B5O8(OH)]*2H2O}} | IMAsymbol = Fon<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 = 6.DA.60 | system = Monoclinic | class = Prismatic (2/m) <br/><small>(same H-M symbol)</small> | symmetry = ''P2''<sub>1</sub>/c | unit cell = | color = Light brown | colour = | habit = | twinning = | cleavage = Perfect {010} | fracture = | tenacity = | mohs = 2.5 - 3 | luster = | streak = | diaphaneity = | gravity = | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = <ref name=mindat/><ref name=atlas>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Fontarnauite Mineralienatlas]</ref> }}
'''Fontarnauite''' is a relatively recently described, rare sulfate, borate mineral with the chemical formula {{chem2|(Na,K)2(Sr,Ca)(SO4)[B5O8(OH)]*2H2O}}. It is found in an evaporite boron deposit. It coexists with other evaporite boron minerals, especially probertite. It is monoclinic, crystallizing in the space group ''P''2<sub>1</sub>/''c''.<ref>García-Veigas, J., Rosell, L., Alcobé, X., Subias, I., Ortí, F., Gündoğan, İ., and Helvaci, C., 2010. Fontarnauite, a New Sulphate-Borate Mineral from the Emet Borate District (Turkey). Revista de la Sociedad Española de Mineralogía 13, 97-98</ref><ref name=mindat>[http://www.mindat.org/min-40279.html Mindat]</ref>
It was named for Ramon Fontarnau i Griera, a materials scientist of the University of Barcelona.<ref name=mindat />
==References== {{reflist}}
Category:Borate minerals Category:Sulfate minerals Category:Sodium minerals Category:Strontium minerals Category:Monoclinic minerals Category:Borate sulfates Category:Minerals in space group 14
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