Vandenbrandeite is a mineral named after a belgian geologist, Pierre Van den Brande, who discovered an ore deposit. It was named in 1932, and has been a valid mineral ever since then.[2]

Vandenbrandeite
General
CategoryMineral
Formula
(repeating unit)
Cu(UO2)(OH)4
IMA symbolVbd[1]
Strunz classification04.GB.45
Dana classification05.03.02.01
Crystal systemTriclinic
Crystal classTriclinic-Pinacoidal
Space groupP1
Unit cell254.99 ų
Identification
ColorBlackish green to dark green with bluish green tint
CleavagePerfect on {001}, {110}
Distinct and also indisctinct in the [001] zone
FractureNone
TenacityBrittle
Mohs scale hardness4
LusterVitreous, sub-vitreous, greasy
StreakGreen
DiaphaneityTransparent, translucent
Specific gravity5.03
Density5.03
Optical propertiesBiaxial (-)
Refractive indexnα = 1.765 - 1.770 nβ = 1.780 - 1.792 nγ = 1.800
Birefringence0.035
PleochroismVisible
2V angleMeasured 90°
Calculated 60°- 88°
DispersionVisible to strong
Ultraviolet fluorescenceNone
Other characteristics Radioactive

Properties

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Vandenbrandeite grows in microcrystals, up to half a millimeter. It may be rounded, lathlike. The crystals are flattened on {001}. It grows in parallel aggregates, in a lamellar, scaly shape.[3] It is tabular, meaning its dimensions in one direction are weak.[4] It is a pleochroic mineral. Depending on the axis the mineral is seen the color of it changes, which is an optical phenomenon. On the x axis it can be seen as a blue-green, and on the z axis is seen as a yellow-green mineral. It is highly stable in the presence of both water and hydrogen peroxide.[2] Vandenbrandeite, due to being strongly radioactive, is usually closely associated with other radioactive minerals.[5] Its radioactive properties is due to its composition. The mineral is made out of 59.27% uranium, which is the main component of the mineral. It has a GRapi (Gamma Ray American Petroleum Institute Units) of 4,352,567.33. It has a concentration of 229.75 measured in GRapi. Other chemical elements included in vandenbrandeite are oxygen (23.9%), copper (15.82%) and hydrogen (1%). Although it is radioactive, the mineral is not fluorescent. It is a secondary mineral. [4]

References

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  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b "Vandenbrandeite". www.mindat.org. Retrieved 2021-09-24.
  3. ^ "Vandenbrandeite". National Gem Lab. 2017-03-27. Retrieved 2021-09-24.
  4. ^ a b "Vandenbrandeite Mineral Data". webmineral.com. Retrieved 2021-06-22.
  5. ^ "Vandenbrandeite".