Exceptional specimen of asbecasite. Exceptional for the size of the crystals, their color and abundance. They show some defined faces and some of them are partially covered by chlorite and fine needles schorl-dravite. Not easy to find on the market. From the type locality: Wannigletscher, Scherbadung area (Monte Cervandone), Kriegalptal, Binntal, Valais, Switzerland, Size: 6.5 x 4.8 x 2.6 cm. Main crystal: 5 x 3 mm. — Photo: Joan Rosell · CC BY-SA 4.0
Asbecasite
A calcium-titanium-beryllium arsenite-silicate from Switzerland's Binn valley.
Intro adapted from Wikipedia (CC BY-SA).
Asbecasite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₃TiAs₆Be₂Si₂O₂₀.
It crystallizes in the hexagonal crystal system (space group P-3c1).
Key properties: Mohs hardness 6.5–7; specific gravity 3.7; Vitreous luster; optically uniaxial.
IMA symbol Abc, IMA status: approved, named in 1965.
On cleft faces in orthogneiss (Cherbadung, Switzerland).
It is found associated with Magnetite, hematite, titanite, apatite, anatase, malachite, azurite, tennantite, molybdenite (Cherbadung, Switzerland).
The name refers to elements in the composition, As, Be, Ca, Si.