Brenkite - Encyclopedia
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 in the World
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