Saleeite

Saleeite

Saleeite (yellow mineral), Chihuahua, Mexico
General
Category Phosphate minerals
Formula
(repeating unit)
Mg(UO2)2(PO4)2·10(H2O)
Strunz classification 08.EB.05
Crystal system Monoclinic
Space group Monoclinic 2/m
Unit cell a = 6.951(3) Å, b = 19.947(8) Å, c = 9.896(4) Å, β = 135.17(2)°; Z=2
Identification
Color Lemon-yellow, straw-yellow, greenish yellow
Crystal habit Crystals are square plates, composite, flattened on {001}, with {001}, {100}, {120}, {012} (pseudotetragonal indices), to 2.5 cm; commonly in subparallel lamellar aggregates.
Cleavage On {001}, perfect; on {010}, {110}, indistinct
Luster Adamantine to waxy
Diaphaneity Transparent to opaque
Specific gravity 3.27
Optical properties Biaxial (-) typically nearly uniaxial
Refractive index nα = 1.554 - 1.559 nβ = 1.570 - 1.582 nγ = 1.571 - 1.585
Birefringence δ = 0.027
Pleochroism X = colorless; Z = pale greenish yellow
2V angle 2V(meas.) = 0–61°
Ultraviolet fluorescence fluoresces bright lemon-yellow under LW UV, pale yellow under SW UV
Other characteristics Radioactive
References [1][2][3][4]

Saleeite is a secondary uranium mineral occurring in the oxidized zones of uranium deposits, or as disseminations in carnotite-bearing sandstones. Its chemical formula is Mg(UO2)2(PO4)2·10(H2O).

It was discovered in 1932 at Shinkolobwe, Katanga Province, Democratic Republic of the Congo, and is named for Belgian mineralogist, Achille Salée (1883-1932), Professor at Université catholique de Louvain, Belgium. It was later determined that the Katanga mineral was meta-saleeite Mg(UO2)2(PO4)2·8(H2O) and the type locality was assigned to the Weißer Hirsch Mine, Neustädtel, Schneeberg District, Erzgebirge, Saxony, Germany.[5][2]

References

  1. Handbook of Mineralogy
  2. 1 2 Mindat.org
  3. Saleeite Mineral Data
  4. Uranium Minerals
  5. Mrose, Mary E. (1950) American Mineralogist: 35: 525
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