{{Infobox mineral | name = Margaritasite | boxwidth = | image = | imagesize = | alt = | caption = | struct image = | struct caption = | struct imagesize = | struct2 image = | struct2 caption = | struct2 imagesize= | SMILES = | Jmol = | category = Carnotite group | formula = (Cs, K, H<sub>3</sub>O)<sub>2</sub>(UO<sub>2</sub>)<sub>2</sub>V<sub>2</sub>O<sub>8</sub>'''·'''H<sub>2</sub>O | IMAsymbol = Mgt<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/E.11-60 | dana = 40.2a.28.2 | system = Monoclinic | class = 2/m – Prismatic | symmetry = ''P2<sub>1</sub>/a'' (no. 14) | unit cell = a = 10.514(3) Å, b = 8.425(3) Å, c = 7.252(5) Å β = 106.01° | color = Yellow | colour = | habit = Tabular crystals, typically massive | twinning = | cleavage = | fracture = | tenacity = | toughness = | mohs = | luster = | streak = | diaphaneity = Translucent | gravity = 5.41 | density = | polish = | opticalprop = Biaxial (−) <br/>α = [< 1.83] (synthetic). β = 2.49(1) γ = > 2.7 | refractive = | birefringence = | pleochroism = | 2V = 45.5◦ | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | Curie temp = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = 25px Radioactive | prop1 = | prop1text = | references = <ref>[http://www.mindat.org/min-2572.html Mindat.org – Margaritasite]</ref><ref name=appleman-evans-1965>{{cite journal |last1=Appleman |first1=D.E. |last2=Evans |first2=H.T. |journal=American Mineralogist |volume=50 |year=1965 |pages=825–842 |title=The crystal structures of synthetic anhydrous carnotite, K2(UO2)2V2O8, and its cesium analogue, Cs2(UO2)2V2O8 |url=https://pubs.geoscienceworld.org/msa/ammin/article-abstract/50/7-8/825/540140 |access-date=30 December 2020}}</ref><ref>{{Cite web |url=http://www.handbookofmineralogy.com/pdfs/margaritasite.pdf |title=Handbook of Mineralogy – Margaritasite |access-date=2013-01-25 |archive-date=2012-10-01 |archive-url=https://web.archive.org/web/20121001043613/http://www.handbookofmineralogy.com/pdfs/margaritasite.pdf |url-status=dead }}</ref> | var1 = | var1text = | var2 = | var2text = | var3 = | var3text = | var4 = | var4text = | var5 = | var5text = | var6 = | var6text = }} '''Margaritasite''' is a yellow, caesium-bearing mineral in the carnotite group. Its chemical formula is (Cs, K, H<sub>3</sub>O)<sub>2</sub>(UO<sub>2</sub>)<sub>2</sub>V<sub>2</sub>O<sub>8</sub>'''·'''H<sub>2</sub>O and its crystal system is monoclinic (space group ''P2<sub>1</sub>/a''<ref name=appleman-evans-1965/>).
==Name and discovery== It was first described in 1982 from the Margaritas uranium deposit in the Peña Blanca district of the municipality of Aldama, in the Mexican state of Chihuahua.
==See also== * List of minerals
==References== {{Reflist}}
Category:Vanadate minerals Category:Caesium minerals Category:Potassium minerals Category:Uranium(VI) minerals Category:Monoclinic minerals Category:Minerals in space group 14 Category:Minerals described in 1982
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