Lepersonnite-(Gd)
Lepersonnite-(Gd) is a very rare rare-earth and uranium mineral with the chemical formula Ca(Gd,Dy)2(UO2)24(SiO4)4(CO3)8(OH)24·48H2O. It occurs associated with bijvoetite-(Y) in the Shinkolobwe deposit in the Democratic Republic of the Congo, famous for rare uranium minerals. Lepersonnite-(Gd) is unique in being the only confirmed mineral with essential gadolinium.[2][4][5] It is named in honour of the Belgian geologist Jacques Lepersonne.
| Lepersonnite-(Gd) | |
|---|---|
![]() Lepersonnite-(Gd) (flat crystals) intergrown in the yellow studtite clusters (needles) and orange curite.  | |
| General | |
| Category | Carbonate mineral | 
| Formula (repeating unit)  | Ca(Gd,Dy)2(UO2)24(SiO4)4(CO3)8(OH)24·48H2O | 
| IMA symbol | Lps-Gd[1] | 
| Strunz classification | 5.EG.10 (10 ed)  8/B.38-10 (8 ed)  | 
| Dana classification | 17.1.12.1 | 
| Crystal system | Orthorhombic | 
| Crystal class | Pyramidal (mm2) and dipyramidal (mmm) | 
| Space group | Pnnm or Pnn2 | 
| Identification | |
| Color | Yellow (bright) | 
| Crystal habit | needle-like crystals in crusts (mammilary) or spherules | 
| Density | 3.97 (measured) | 
| Optical properties | Biaxal (-) | 
| Refractive index | nα = 1.638, nβ = 1.666, nγ = 1.682 | 
| 2V angle | 73° (calculated) | 
| Other characteristics | |
| References | [2][3][4] | 
References
    
- 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.
 - Deliens, M., and Piret, P., 1982. Bijvoetite et lepersonnite, carbonates hydrates d'uranyle et des terres rares de Shinkolobwe, Zaïre. Canadian Mineralogist 20, 231–238.
 - "Lepersonnite-(Gd) - Handbook of Mineralogy" (PDF). Handbookofmineralogy.org. Retrieved 2016-03-08.
 - "Lepersonnite-(Gd): Lepersonnite-(Gd) mineral information and data". Mindat.org. Retrieved 2016-03-04.
 - Gadolinium: The mineralogy of gadolinium - Mindat. org
 
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