Chervetite
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 3.0)
Mineral NameChervetite
Chemical FormulaPb2(UO2)2(VO4)2·4H2O
Mohs Hardness2.5
Crystal Systemmonoclinic
Streak Colorpale yellow
Cleavagegood on {001}
Fractureuneven
Specific Gravity5.86
Colorsgrey, brownish-grey, yellowish-brown
Transparencytranslucent to opaque
Type LocalityMounana Mine, Franceville, Haut-Ogooué, Gabon
Mineral Groupphosphates, arsenates, vanadates (uranyl vanadate)
Usescollector
Associated Mineralsfrancevillite
Rarityrare
Description
Chervetite appears as brownish-grey, blocky to tabular crystals with a layered texture, embedded within a matrix of fine-grained, yellowish-green Francevillite. The Chervetite crystals are scattered across the surface, contrasting with the more abundant Francevillite.
Geological Context
Chervetite is a rare secondary uranium mineral that forms in the oxidized zones of uranium-vanadium deposits. It typically occurs as an alteration product of primary uranium minerals in environments rich in lead and vanadium.
