Uranophane

nesosilicate

Formula: Ca(UO2)2(SiO3OH)2.5H2O
Nesosilicate (insular SiO4 groups), uranium mineral
Specific gravity: 3.83 to 3.90
Hardness: 2½ to 3
Streak: Yellowish white
Colour: Light yellow, lemon-yellow, honey-yellow, straw-yellow, green-yellow
Environments:

Pegmatites
Hydrothermal environments

Uranophane occurs in pegmatites, and as an alteration product of uraninite in oxidised uranium deposits (Dana, Webmin). It is the most common uranium silicate mineral, and occurs at practically every locality where pitchblende is found (AM 40.634, HOM). Uranophane is associated with other secondary uranium minerals, including autunite, torbernite, kasolite, schoepite, meta-autunite, phosphuranylite and sklodowskite (AM 40.634, HOM).

The type Locality is Miedzianka, Gmina Janowice Wielkie, Jelenia Góra Co, Lower Silesian Voivodeship, Poland.

At Shaba, Zaire, uranophane occurs as pseudomorphs after uraninite and in association with kasolite, rutherfordine and less commonly soddyite (Dana).

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