Lepersonnite-(Gd) | |
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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 |
Specific gravity | Fass |
Density | 3.97 (measured) |
Optical properties | Biaxal (-) |
Refractive index | nα = 1.638, nβ = 1.666, nγ = 1.682 |
2V angle | 73° (calculated) |
Other characteristics | Radioactive |
References | [2][3][4] |
Lepersonnite-(Gd) is a very rare-earth element and uranium mineral with the chemical formula Ca(Gd,Dy)2(UO2)24(SiO4)4(CO3)8(OH)24·48H2O. It occurs with bijvoetite-(Y) in the Shinkolobwe deposit in the Democratic Republic of the Congo, famous for rare uranium minerals. It was the first confirmed mineral with essential gadolinium[2][4][5] and remained the only gadolinium dominant species until the description of Monazite-(Gd) in 2023.
It was first described in 1982 and is named after the Belgian geologist Jacques Lepersonne.