*** Welcome to piglix ***

Wyartite

Wyartite
General
Category Carbonate minerals
Formula
(repeating unit)
CaU5+
(UO
2
)
2
(CO
3
)O
4
(OH)
·7H2O
Strunz classification 5.EA.15
Crystal system Orthorhombic
Crystal class Disphenoidal (222)
Space group: (222)
Space group P212121
Identification
Color black, violet-black (fresh); yellowish brown, greenish brown (exposed)
Luster vitreous, sub-metallic, dull
Diaphaneity transparent, translucent, opaque
References

Wyartite CaU5+
(UO
2
)
2
(CO
3
)O
4
(OH)
·7H2O is a uranium bearing mineral named after Jean Wyart (1902–1992), mineralogist at the Sorbonne, Paris. It has greenish-black, black, or violet-black, translucent to opaque orthorhombic crystals. A hardness of 3 - 4 Mohs. Its other names are Ianthinite (of Bignand), Wyartit and Wyartita. It belongs to the uranium carbonate group of minerals. It is found next to rutherfordine in Shinkolobwe, Shaba, Zaire.

Determination of the structure of wyartite provided the first evidence for a pentavalent uranium mineral. Like all uranium minerals it is radioactive.



...
Wikipedia

...