Carnotite

Formula: K2(UO2)2(VO4)2 · 3H2O

Colour: Bright yellow, yellow, greenish yellow

Lustre: Sub-Vitreous, Resinous, Waxy, Silky, Dull, Earthy

Hardness: 2

Specific Gravity: 4.70

Crystal System: Monoclinic

Member of: Carnotite Group

Name: Named in 1899 by Charles Friedel and Édouard Cumenge in honor of Marie-Adolphe Carnot [1839-1920], French mining engineer and chemist, professor at École des Mines. The unrelated mineral silicocarnotite is also named after him.

Type Locality: Rajah Mine (Big Chief No. 2; Dullan claim), Uravan Mining District, Montrose County, Colorado – USA

A secondary mineral resulting from the alteration of Uraninite, Montroseite, or Davidite. Occurs in sandstones, especially in paleochannels, near fossil carbonaceous matter, in calcretes and near playas. Chemically close to vandermeerscheite.