Wyartite
A greenish-black uranium carbonate named for Sorbonne mineralogist Jean Wyart.
Intro adapted from Wikipedia (CC BY-SA).
Wyartite is an IMA-recognized mineral species in the carbonate class, with the chemical formula CaU⁵⁺(UO₂)₂(CO₃)O₄(OH)·7H₂O.
It crystallizes in the orthorhombic crystal system (space group P2_12_12_1).
Key properties: Mohs hardness 3–4; specific gravity 4.69; Brownish violet streak; Dull, vitreous to submetallic on cleavages luster; optically biaxial.
IMA symbol Wya, IMA status: approved, named in 1959.
A rare secondary mineral formed as an alteration product of uraninite in the oxide zone of a uranium deposit.
It is found associated with Wölsendorfite, rutherfordine, uranophane, masuyite, urancalcarite, uraninite.
The mineral was named to honor Dr. Jean Wyart (1902–1992), French crystallographer, Professor of Mineralogy, Sorbonne, Paris, France.