ESKEBORNITE

    Class : Sulfides and sulfosalts
    Subclass : Selenides
    Crystal system : Cubic
    Chemistry : CuFeSe2
    Rarity : Rare

Eskebornite is the selenium equivalent of chalcopyrite. It is a mineral from hydrothermal selenium deposits (frequently uranium deposits). It owes its name to its place of discovery : Eskeborn in the German Harz. It occurs in tabular crystals of 1 mm maximum, and in xenomorphic coatings mixed with other selenides (clausthalite, berzelianite, umangite, etc...). Its color is copper yellow to brass yellow but it quickly tarnishes to a dark brown turning black. It is a very accessory selenium ore.

Main photo : Eskebornite from Bukov Mine, RCzech Republic © Stephan Wolfsried

Eskebornite in the World

Eskebornite is known from the selenium-rich uranium deposits of Predborice and Bukov (Czech Republic), and from the large Canadian deposits of Lake Athabasca (Uranium City). It is also present in the selenide veins of Tilkerode (Harz, Germany) and Cacheuta (Mendoza, Argentina).

Eskebornite in France

In France, we know of beautiful coatings of eskebornite in the pitchblende and selenide vein of Chaméane (Puy-de-Dôme).

Twinning

No twin known for this mineral species.

Fakes and treatments

No fake listed for this mineral species.


Hardness : 3 to 3.5
Density : 5.35
Fracture : Undeterminated
Streak : Black

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

Solubility : -


Magnetism : Paramagnetic
Radioactivity : None