Uranophane

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Uranophane
Uranophane.jpg
General
CategoryUranyl neso- and polysilicates
Formula
(repeating unit)
Ca(UO2)2[HSiO4]2·5H2O
Strunz classification9.AK.15
Crystal systemMonoclinic
Crystal classSphenoidal (2)
(same H-M symbol)
Space groupP21
Unit cella = 15.85 Å, b = 6.98 Å
c = 6.64 Å; β = 97.45°; Z = 2
Identification
Formula mass586.36 g/mol
ColorLight yellow, lemon-yellow, honey-yellow, straw-yellow, green-yellow
Crystal habitCrystals occur as stellate needle aggregates; as fibrous crusts, and massive
Cleavage{100} Perfect
FractureUneven
TenacityBrittle
Mohs scale hardness2.5
LusterVitreous to pearly; waxy or dull when massive
StreakYellowish white
DiaphaneityTranslucent to subtranslucent
Specific gravity3.81 - 3.90
Optical propertiesBiaxial (-)
Refractive indexnα = 1.643 nβ = 1.666 nγ = 1.669
Birefringenceδ = 0.026
PleochroismWeak; X = colorless; Y = pale canary-yellow; Z = canary-yellow
2V angle32° to 45°, measured
Ultraviolet fluorescenceWeak yellow-green under both short and long UV
Other characteristicsRadioactive
References[1][2][3]

Uranophane (Ca(UO2)2(SiO3OH)2·5H2O), also known as uranotile, is a rare calcium uranium silicate hydrate mineral that forms from the oxidation of other uranium-bearing minerals. It has a yellow color and is radioactive.

References[edit]