CAFARSITE

    Class : Oxides and hydroxides
    Subclass : Arsenites
    Crystal system : Cubic
    Chemistry : Ca8(Ti,Fe,Mn)6-7(AsO3)12 4H2O
    Rarity : Very rare

Cafarsite is an extremely rare arsenate of calcium, manganese and titanium, known mainly in the cracks of metamorphic rocks. It is a mineral which owes its name to its chemical composition (calcium + iron + arsenic). It occurs in cubo-octahedra, octahedra, cubes and pentagonododecahedra, sometimes centimetric, dark brown to red-brown in color, frequently altered.

Main photo : Cafarsite from Monte Cervandone, Italy © Rob Lavinsky

Cafarsite from Monte Cervandone, Italy © Enrico Bonacina
Cafarsite from the Wanni glacier, Valais, Switzerland © Stephan Wolfsried
Cafarsite from the Wanni glacier, Valais, Switzerland © Beppe Finello
Cafarsite from the Wanni glacier, Valais, Switzerland © Stephan Wolfsried

Cafarsite in the World

The best crystals, reaching up to 5 cm, are found in the orthogneisses, on the Italian and Swiss slopes of Mount Cherbadung (the "Pizzo Cervandone" in Italy). Cockarsite is also described at the Hemlo gold mine (Canada).

Cafarsite in France

is not present in the French underground.

Twinning

No twin known for this mineral species.

Fakes and treatments

No fake identified for this mineral species.


Hardness : 5.5 to 6
Density : 3.9
Fracture : Conchoidal
Streak : Brown-yellow

TP : Opaque
RI : 2.2
Birefringence : 0
Optical character : None
Pleochroism : None
Fluorescence : None

Solubility : -

Magnetism : None
Radioactivity : None