Reinhardbraunsite Locality: Caspar quarry, Bellerberg volcano, Ettringen, Mayen, Eifel Mts, Rhineland-Palatinate, Germany Pink Reinhardbraunsite in matrix. Field of view 6 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Reinhardbraunsite
Reinhardbraunsite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₅(SiO₄)₂(OH)₂.
It crystallizes in the monoclinic crystal system (space group P2_1/b). It is a member of the Humite structural group.
Key properties: Mohs hardness 5–6; specific gravity 2.85; White streak; Vitreous luster; optically biaxial.
IMA symbol Rbn, IMA status: approved, named in 1980.
Found in contact metamorphosed and metasomatized calcium-rich xenoliths in scoria.
It is found associated with Ellestadite, cuspidine, gehlenite, brownmillerite, mayenite, periclase.
The name refers to Dr. Reinhard Brauns (1861–1937), Professor of Mineralogy at the University of Bonn, Bonn, Germany.