Images
Formula: {(NH4)2[Ca2(H2 O)14](H2 O)2}{V10O28}
Decavanadate
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
Environments
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.
Localities
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).
Back to Minerals