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]).
| Margaritasite | |
|---|---|
| General | |
| Category | Carnotite group |
| Formula (repeating unit) | (Cs, K, H3O)2(UO2)2V2O8·H2O |
| IMA symbol | Mgt[1] |
| Strunz classification | 7/E.11-60 |
| Dana classification | 40.2a.28.2 |
| Crystal system | Monoclinic |
| Crystal class | 2/m – Prismatic |
| Space group | P21/a (no. 14) |
| Unit cell | a = 10.514(3) Å, b = 8.425(3) Å, c = 7.252(5) Å β = 106.01° |
| Identification | |
| Color | Yellow |
| Crystal habit | Tabular crystals, typically massive |
| Diaphaneity | Translucent |
| Specific gravity | 5.41 |
| Optical properties | Biaxial (−) α = [< 1.83] (synthetic). β = 2.49(1) γ = > 2.7 |
| 2V angle | 45.5◦ |
| Other characteristics |  Radioactive |
| References | [2][3][4] |
Name and discovery
editIt 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
editReferences
edit- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ Mindat.org – Margaritasite
- ^ a b Appleman, D.E.; Evans, H.T. (1965). "The crystal structures of synthetic anhydrous carnotite, K2(UO2)2V2O8, and its cesium analogue, Cs2(UO2)2V2O8". American Mineralogist. 50: 825–842. Retrieved 30 December 2020.
- ^ "Handbook of Mineralogy – Margaritasite" (PDF). Archived from the original (PDF) on 2012-10-01. Retrieved 2013-01-25.