VÉSIGNIÉITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Anhydrous vanadates
    Crystal system : Monoclinic
    Chemistry : BaCu3(VO4)2(OH)2
    Rarity : Rare

Vésigniéite is a copper and barium vanadate discovered in 1955. This mineral forms in the oxidation zone of deposits containing vanadium. It was named in honor of the French colonel Louis Vésignié who was certainly the greatest collector of minerals of his time and a great donor, since he bequeathed the 40,000 samples of his collection to the Faculty of Sciences of Paris as well as to the Museum of Natural History of Paris. Vesignieite forms aggregates of thin lamellae not exceeding one millimeter, pseudohexagonal in appearance, olive green to yellow-green in color.

Main photo : Vésigniéite from Bardon Hill Quarry, England © Ru Smith

Vésigniéite from Mashamba West Mine, DR Congo © Vincent Bourgouin
Vésigniéite from Mashamba West Mine, DR Congo © Vincent Bourgouin
Vésigniéite from New Cliffe Hill Quarry, England © Steve Rust
Vésigniéite from Roua Mines, Daluis, Alpes-Maritimes, France © Pascal Chollet

Vésigniéite in the World

The finest samples of vésigniéite come from calcite and baryte geodes extracted from the manganese deposit of Friedrichroda (Germany), but this mineral has also been described in several other deposits, notably in the Urals, Morocco, the United States (Monument Valley in Arizona), and England.

Vésigniéite in France

In France, vésigniéite is reported in the copper mineralizations of the Roua pass, near Daluis (Alpes-Maritimes).

Twinning

Twinning is known on {001}, sometimes polysynthetic.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 3 to 4
Density : 4.56
Fracture : Undetermined
Streak : Green

TP : Translucent
RI : 2.053 to 2.133
Birefringence : 0.080
Optical character : Biaxial -
Pleochroism : None
Fluorescence : None

Solubility : -

Magnetism : NoneRadioactivity : None