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.^[4] It has a hardness of 3 to 4 on the Mohs scale. 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.^[4]

Wyartite
General
Category	Carbonate minerals
Formula (repeating unit)	CaU5+ (UO 2) 2(CO 3)O 4(OH)·7H2O
IMA symbol	Wya[1]
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
Other characteristics	Radioactive
References	[2][3]

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