Vandenbrandeite

Oxide mineral
(repeating unit)Cu(UO2)(OH)4IMA symbolVbd[1]Strunz classification04.GB.45Dana classification05.03.02.01Crystal systemTriclinicCrystal classTriclinic-PinacoidalSpace groupP1Unit cell254.99 ųIdentificationColorBlackish green to dark green with bluish green tintCleavagePerfect on {001}, {110}
Distinct and also indisctinct in the [001] zoneFractureNoneTenacityBrittleMohs scale hardness4LusterVitreous, sub-vitreous, greasyStreakGreenDiaphaneityTransparent, translucentSpecific gravity5.03Density5.03Optical propertiesBiaxial (-)Refractive indexnα = 1.765 - 1.770 nβ = 1.780 - 1.792 nγ = 1.800Birefringence0.035PleochroismVisible2V angleMeasured 90°
Calculated 60°- 88°DispersionVisible to strongUltraviolet fluorescenceNoneOther characteristics Radioactive

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]

Properties

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

  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".