Lepersonnite-(Gd)

Lepersonnite-(Gd) is a very rare rare-earth and uranium mineral with the 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.[1][3][4] 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
CategoryCarbonate mineral
Formula
(repeating unit)
Ca(Gd,Dy)2(UO2)24(SiO4)4(CO3)8(OH)24•48H2O
Strunz classification5.EG.10 (10 ed)
8/B.38-10 (8 ed)
Dana classification17.1.12.1
Crystal systemOrthorhombic
Crystal classPyramidal (mm2) and dipyramidal (mmm)
Space groupPnnm or Pnn2
Identification
ColorYellow (bright)
Crystal habitneedle-like crystals in crusts (mammilary) or spherules
Density3.97 (measured)
Optical propertiesBiaxal (-)
Refractive indexnα = 1.638, nβ = 1.666, nγ = 1.682
2V angle73° (calculated)
Other characteristics Radioactive
References[1][2][3]

References

  1. 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.
  2. "Lepersonnite-(Gd) - Handbook of Mineralogy" (PDF). Handbookofmineralogy.org. Retrieved 2016-03-08.
  3. "Lepersonnite-(Gd): Lepersonnite-(Gd) mineral information and data". Mindat.org. Retrieved 2016-03-04.
  4. Gadolinium: The mineralogy of gadolinium - Mindat. org


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