DESCLOIZITE
Class : Phosphates, arsenates, vanadates
Subclass : Anhydrous vanadate
Crystal system : Orthorhombic
Chemistry : PbZn(VO4)(OH)
Rarity : Uncommon
Descloizite is an oxidation mineral of basic metalliferous deposits (Pb, Zn, Cu) containing vanadium and is found mainly in the hot desert regions of the globe. It forms a complete series with the mottramite, its copper equivalent. It is a mineral that owes its name to the French mineralogist Alfred Louis Olivier Legrand Descloizeaux who described the mineral. Descloizite occurs as short, sometimes elongated, prismatic crystals or as octahedra, generally grouped in incrustations, in parallel growth aggregates with a tree-like appearance, or in botryoidal masses with a fibrous structure. Its color is brownish red, sometimes brown-orange to orange or metallic gray. Descloizite can exceptionally be exploited as vanadium ore, but presents no other particular use, its crystals are appreciated and sought after by mineral collectors.
Main photo : Descloizite crystals from Berg Aukas, Namibia
Descloizite in the World
Descloizite in France
In France, descloizite was identified as microcrystals in the Cap Garonne mine in Var department but also in Longefay (Rhône) and in the Rivet quarry at Réalmont (Tarn).
Fakes and scams
No fake registered for this mineral species.
Hardness : 3 to 3.5
Density : 6.2
Fracture : Irregular to sub-conchoidal
Streak : Orange to brown
TP : Opaque to transparent
IR : 2.18 to 2.35
Birefringence : 0.165
Optical character : Biaxial -
Pleochroism : Weak to strong
Fluorescence : None
Solubility : Acids
Magnetism : None
Radioactivity : None