MOUNANAITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Anhydrous vanadates
    Crystal system : Monoclinic
    Chemistry : PbFe2(VO4)2(OH)2
    Rarity : Very rare

Mounanaite is an iron and lead vanadate discovered in the surface oxidation zone of the Mounana uranium deposit (Gabon) from which it takes its name. Mounanaite forms tiny elongated pseudohexagonal or diamond-shaped crystals of a reddish-brown hue of sub-millimeter size, agglomerated in encrustations. It is associated with goethite and other vanadates, notably uranium (francevillite and curienite).

Main photo : Mounanaite from Mounana Mine, Gabon © Stephan Wolfsried

Mounanaite in the World

Mounanaite is only known at the Mounana Mine (Gabon) and at Monte Toff (Italy).

Mounanaite in France

Mounanaite is not known in the French underground.

Twinning

Twins are common by rotation around [001] or on {1-11}.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 4.5
Density : 4.85
Fracture : Undetermined
Streak : Undetermined

TP : Translucent to transparent
RI : -
Birefringence : -
Optical character : Biaxial
Pleochroism : Strong
Fluorescence : None

Solubility : -

Magnetism : NoneRadioactivity : None