Wyartite CaU5+ (UO 2) 2(CO 3)O 4(OH)·7H2O is a uranium named after Jean Wyart , 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 , Shaba
Determination of the structure of wyartite provided the first evidence for a pentavalent uranium mineral. Like all uranium minerals it is radioactive.