Images
Formula: Ca(U6+O2)2(SiO3OH)2.5H2O
Nesosilicate (insular SiO4 groups), uranophane group,
uranyl mineral
Crystal System: Monoclinic
Specific gravity: 3.8 to 3.91 measured, 3.78 calculated
Hardness: 2½ to 3
Streak: Yellowish white
Colour: Light yellow, lemon-yellow, honey-yellow, straw-yellow, green-yellow
RADIOACTIVE
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).
Localities
At the Margaritas No. 1 Mine, Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, Mexico,
uranophane crystallised inside cavities lined with glossy dark brown to black material that might be
goethite
(Mindat photo).
Uranophane from the Margaritas No. 1 Mine -
Image
The type Locality is Miedzianka, Gmina Janowice Wielkie, Jelenia Góra Co, Lower Silesian Voivodeship, Poland.
Uranophane from the Miedzianka Field -
Image
At Shaba, Zaire, uranophane occurs as pseudomorphs after
uraninite and in association with
kasolite, rutherfordine and less commonly
soddyite
(Dana).
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