Saleeite
Appearance
Saleeite | |
---|---|
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]