Zeunerite

Zeunerite is a green copper uranium arsenate mineral with formula Cu(UO2)2(AsO4)2•(10-16)H2O. It is a member of the autunite group. The associated mineral metazeunerite is a dehydration product of zeunerite.

Zeunerite
General
CategoryArsenate mineral
Formula
(repeating unit)
Cu(UO2)2(AsO4)2•(10-16)H2O
Strunz classification8.EB.05
Dana classification40.02a.14.01
Crystal systemTetragonal
Crystal classDitetragonal dipyramidal (4/mmm)
H-M symbol: (4/m 2/m 2/m)
Space groupP4/nnc
Identification
ColorYellow-green, emerald-green
Crystal habitCrystals flat tabular on {001}, commonly subparallel to micaceous
Cleavage{001} perfect, {100}, distinct
Mohs scale hardness2.5
LusterVitreous
Streakpale green
DiaphaneityTransparent, becoming translucent on dehydration
Specific gravity3.2 - 3.4
Optical propertiesUniaxial (-)
Refractive indexnω = 1.610 - 1.613 nε = 1.582 - 1.585
Birefringenceδ = 0.028
PleochroismVisible
Other characteristics Radioactive
References[1][2][3]

Zeunerite occurs as a secondary mineral in the oxidized weathering zone of hydrothermal uranium ore deposits which contain arsenic. Olivenite, mansfieldite, scorodite, azurite and malachite are found in association with zeunerite.[1]

It was first described in 1872 for an occurrence in the Schneeberg District, Erzgebirge, Saxony, Germany. It was named for Gustav Anton Zeuner (1828–1907).[2]

References

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