Zeunerite

Zeunerite
General
Category	Arsenate mineral
Formula (repeating unit)	Cu(UO2)2(AsO4)2·(10-16)H2O
IMA symbol	Zeu[1]
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	[2][3][4]

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 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.[2]

It was first described in 1872 for an occurrence in the Schneeberg District, Ore Mountains, Saxony, Germany. It was named for Gustav Anton Zeuner (1828–1907).[3]

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. Handbook of Mineralogy
3. Mindat
4. Webmineral data