BRENKITE

    Class : Carbonates, nitrates, borates
    Subclass : Anhydrous carbonates
    Crystal system : Orthorhombic
    Chemistry : Ca2CO3F2
    Rarity : Very rare

Brenkite is an extremely rare calcium fluoro-carbonate found in cracks and voids of leucite phonolites in the Eifel massif. It precisely owes its name to its place of discovery : Schellkopf, Brenk, Eifel, Germany. It occurs in small colorless lamellar crystals, not exceeding 1 mm, united in radiated aggregates.

Main photo : Brenkite from Schellkopf, Brenk, Eifel, Germany © Volker Betz

Brenkite from Schellkopf, Brenk, Eifel, Germany © Christof Schäfer
Brenkite from Schellkopf, Brenk, Eifel, Germany © Christof Schäfer
Brenkite and zeophyllite from Schellkopf, Brenk, Eifel, Germany © Volker Betz
Brenkite from Schellkopf, Brenk, Eifel, Germany © Christof Schäfer

Brenkite in the World

The most beautiful known brenkite crystals come from Schellkopf (Brenk, Eifel, Germany), its type locality, they are millimetric in size. Brenkite has also been described in the alkaline massif of Tajno (Poland), at Sörvik (Sweden) and at the Point of Rocks quarry (New Mexico).

Brenkite in France

Brenkite is not present in the French underground.

Twinning

No twin known for this mineral species.

Fakes and treatments

No fake recorded for this mineral species.


Hardness : 5
Density : 3.10
Fracture : Irregular
Trace : White

TP : Translucent
RI : 1.525 to 1.593
Birefringence : 0.068
Optical character : Biaxial -
Pleochroism : None
Fluorescence : None

Solubility : Hydrochloric acid

Magnetism : None
Radioactivity : None