Images
Formula: Cu3(VO4)2
Anhydrous vanadate, paramorph of
pseudolyonsite
Crystal System: Triclinic
Specific gravity: 4.50 calculated
Colour: Black
Luminescence: Not fluorescent under short wave or long wave UV
Environments
Localities
The type locality, the Izalco Volcano, Sonsonate Department, El Salvador, is a
basaltic and andesitic
stratovolcano that has been intermittently active since its birth in 1770. In 1963,
shcherbinaite, the first-known hightemperature
vanadium mineral, was discovered in the summit crater fumaroles. Since that
time, five other high-temperature vanadium sublimates have been isolated from
the fumarolic mineral suite. These are bannermanite and four
copper vanadates,
stoiberite, fingerite,
ziesite and mcbirneyite. These
minerals formed as sublimates from vanadium-bearing gases at temperatures up to
760oC.
Mcbirneyite was found in the outer sulphate zone of one of five major fumaroles in the summit crater, indicating
a sublimation temperature between 100 and 200oC. It is associated with
fingerite, thénardite and
euchlorine. Approximately ten crystals of mcbirneyite have been
isolated, all less than 200 microns in size
(Journal of Volcanology and Geothermal Research 33.183-190).
Back to Minerals