Bellbergite Locality: Caspar quarry, Bellerberg volcano, Ettringen, Mayen, Eifel Mts, Rhineland-Palatinate, Germany Colourless to white crystals of Bellbergite (analysed). Field of view 2 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Bellbergite
Bellbergite is an IMA-recognized mineral species in the silicate class, with the chemical formula (K,Ba,Sr)₂Sr₂Ca₂(Ca,Na)₄(Si,Al)₃₆O₇₂·30H₂O.
It crystallizes in the hexagonal crystal system (space group P6_3/mmc).
Key properties: Mohs hardness 5; specific gravity 2.2; [White.] streak; Vitreous luster; optically uniaxial.
IMA symbol Blb, IMA status: approved, named in 1990.
Found in leucite tephrite lava at contacts between lava and calcium-rich xenoliths.
It is found associated with Sanidine, clinopyroxene, pyrrhotite, thompsonite, ettringite, willhendersonite, gismondine, jasmundite, mayenite, srebrodolskite, calcic olivine, portlandite.
The name refers to its occurrence at the Bellerberg (also Bellberg) volcano, Germany.