Margaritasite Explained

Margaritasite
Category:	Carnotite group
Formula:	(Cs, K, H3O)2(UO2)2V2O8·H2O
Imasymbol:	Mgt^[1]
Strunz:	7/E.11-60
Dana:	40.2a.28.2
System:	Monoclinic
Class:	2/m – Prismatic
Symmetry:	P21/a (no. 14)
Unit Cell:	a = 10.514(3) Å, b = 8.425(3) Å, c = 7.252(5) Åβ = 106.01°
Color:	Yellow
Habit:	Tabular crystals, typically massive
Diaphaneity:	Translucent
Gravity:	5.41
Opticalprop:	Biaxial (−) α = [< 1.83] (synthetic). β = 2.49(1) γ = > 2.7
2V:	45.5◦
Other:	Radioactive
References:	^[2] ^[3] ^[4]

Margaritasite is a yellow, caesium-bearing mineral in the carnotite group. Its chemical formula is (Cs, K, H₃O)₂(UO₂)₂V₂O₈·H₂O and its crystal system is monoclinic (space group P2₁/a^[3]).

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

Notes and References

1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3 . 291–320. 10.1180/mgm.2021.43 . 2021MinM...85..291W . 235729616 . free.
2. http://www.mindat.org/min-2572.html Mindat.org – Margaritasite
3. Appleman . D.E. . Evans . H.T. . American Mineralogist . 50 . 1965 . 825–842 . The crystal structures of synthetic anhydrous carnotite, K2(UO2)2V2O8, and its cesium analogue, Cs2(UO2)2V2O8 . 30 December 2020.
4. Web site: Handbook of Mineralogy – Margaritasite . 2013-01-25 . 2012-10-01 . https://web.archive.org/web/20121001043613/http://www.handbookofmineralogy.com/pdfs/margaritasite.pdf . dead .