Berzelianite - Encyclopedia

    Class : Sulfides and sulfosalts
    Subclass : Selenides
    Crystal System : Cubic
    Chemistry : Cu2Se
    Rarity : Rare

Berzelianite is a rare copper selenide, present in various hydrothermal environments : calcite veins in serpentinites (Skrikerum, Sweden), hydrothermal polymetallic dolomite veins (Clausthal and Tilkerode in the Harz, Germany), iron ores (Lerbach, Germany ), hydrothermal uranium deposit in a sedimentary context (Eldorado, Saskatchewan, Canada). It is the seleniferous equivalent of chalcocite but it is much rarer than this one. It was named in honor of the Swedish chemist Jöns Jacob Berzelius who carried out the first analyses. There are no known crystals, berzelianite forms thin veinlets, dendritic crusts and fine scattered patches, of a bluish silver-white color dulling to lead gray or yellowish gray.

Main photo : Berzelianite from Bukov Mine, Rocná deposit, Czech Republic © Zbynek Burival

Berzelianite in the World

In addition to the localities already mentioned in the description, berzelianite is also present in the uraniferous veins of Moravia, in the Czech Republic (district of Tisnova) and in Australia (Kalgoorlie, El Sharana).

Berzelianite in France

In France, berzelianite is found in pitchblende from Chaméane (Puy-de-Dôme).

Twinning and special crystallizations

No known twin for this mineral species.

Fakes and treatments

No fake or treatment recorded for this mineral species.

Hardness : 2
Density : 6.71
Fracture : Irregular
Trace : Shiny to shiny black

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

Solubility : Nitric acid

Magnetism : None
Radioactivity : None