Formula: {(NH4)2[Ca2(H2 O)14](H2 O)2}{V10O28}
Crystal System: Triclinic
Specific gravity: 2.352 calculated
Hardness: 2
Streak: Yellow
Colour: Yellow-orange
Luminescence: Not fluorescent under UV
Solubility: Dissolves instantly in cold, dilute hydrochloric acid and slowly in water

Sedimentary environments
Hydrothermal environments

Wernerbaurite was approved in 2012 and redefined in 2015, but to date (November 2022) it has been reported only from the type locality.


At the type Llocality, the Saint Jude mine, Slick Rock Mining District, San Miguel county, Colorado, USA, wernerbaurite is rare. It was found on corvusite-montroseite-bearing sandstone blocks and closely associated with calciodelrioite, gypsum, huemulite, hughesite, metarossite, pascoite and rossite. Other minerals found in the same area in the mine include schindlerite, delrioite, hendersonite, nashite and powellite.
The minerals form from the oxidation of corvusite-montroseite assemblages in a moist environment. Mining operations have exposed unoxidised and oxidised phases. Under ambient temperatures and generally oxidising near-surface environments, water reacts with pyrite in the deposit to form aqueous solutions with relatively low pH (acid). The various secondary vanadate phases that formed depend upon the ambient conditions and on the presence of other cations such as Na+, Ca2+, Mg2+ and Al3+.
Crystals of wernerbaurite occur as thin flattened tablets with stepped faces and square to octagonal outlines, up to ~1 mm in size. It is yellow-orange with a yellow streak, transparent and with a subadamantine lustre (CM 51.297-312).

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