Autunite
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 4.0)
Mineral NameAutunite
Chemical FormulaCa(UO₂)₂(PO₄)₂·10-12H₂O
Mohs Hardness2
Crystal Systemtetragonal
Lustervitreous
Streak Colorpale yellow
Cleavageperfect on {001}
Fractureuneven
Specific Gravity3.1
Colorsyellow-green, bright green
Transparencytransparent
Type LocalityLes Oudots Quarry, Issy-l'Evêque, Saône-et-Loire, Burgundy, France
Mineral GroupPhosphates
Usesuranium ore, collector
Associated Mineralstorbernite, uraninite, meta-autunite
Rarityuncommon
Description
This specimen displays bright yellow-green, platy to tabular crystals forming a crust on a rock matrix, exhibiting strong green fluorescence under ultraviolet light.
Geological Context
Autunite is a secondary uranium mineral, typically forming in the oxidized zones of uranium-bearing deposits, often found in granite pegmatites or hydrothermal veins where primary uranium minerals have altered.
