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Zeunerite

Zeunerite
Zeunerite 2 on quartz Copper urano-arsenate Perry Jones Group Plumas County Calfornia 1969.jpg
General
Category Arsenate mineral
Formula
(repeating unit)
Cu(UO2)2(AsO4)2•(10-16)H2O
Strunz classification 8.EB.05
Dana classification 40.02a.14.01
Crystal system Tetragonal
Crystal class Ditetragonal dipyramidal (4/mmm)
H-M symbol: (4/m 2/m 2/m)
Space group P4/nnc
Identification
Color Yellow-green, emerald-green
Crystal habit Crystals flat tabular on {001}, commonly subparallel to micaceous
Cleavage {001} perfect, {100}, distinct
Mohs scale hardness 2.5
Luster Vitreous
Streak pale green
Diaphaneity Transparent, becoming translucent on dehydration
Specific gravity 3.2 - 3.4
Optical properties Uniaxial (-)
Refractive index nω = 1.610 - 1.613 nε = 1.582 - 1.585
Birefringence δ = 0.028
Pleochroism Visible
Other characteristics Radioactive
References

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. Metazeunerite is a dehydration product.

It 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.

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).


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