Wyartite
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. Greenish black, black, black violet in color, translucent to opaque orthorhombic crystals presentantion. 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.