FERRITUNGSTITE

    Class : Sulfates, chromates, molybdates
    Subclass : Tungstates
    Crystal system : Cubic
    Chemistry : (W,Fe)2(O,OH)6 nH2O
    Rarity : Uncommon

Ferritungstite is an uncommon mineral, formed by surface alteration of wolframite and scheelite. It was named thus in reference to its chemical composition (iron + tungsten). Formerly considered a species in its own right, it is today described as a variety of ferric hydrokenoelsmoreite. It usually constitutes orange to brownish powdery coatings, associated with tungstite, in the oxidized superficial parts of hydrothermal tungsten deposits (high temperature veins, skarns, stratoid deposits, etc...).

Main photo : Ferritungstite from Hingston Down Quarry, Cornwall, England © Ian Jones

Ferritungstite in the World

Ferritungstite is known from quite a number of deposits around the world, it was notably described in English Cornwall and at the Clara Mine (Germany).

Ferritungstite in France

In France, ferritungstite is known in good specimens in the veins of Meymac (Corrèze) but also of Bertrande (Haute-Vienne), where it was relatively abundant.

Twinning

A cyclic twin with 6 faces according to the spinel twin law and known as well as an interpenetration twin.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 3
Density : Undeterminated
Fracture : Irregular
Streak : White

TP : Opaque
RI : 2.24
Birefringence : 0
Optical character : None
Pleochroism : None
Fluorescence : None

Solubility : Acids


Magnetism : None
Radioactivity : None