Breyite
A high-pressure calcium silicate found only as inclusions inside deep-origin diamonds — the second most common such inclusion after ferropericlase.
Intro adapted from Wikipedia (CC BY-SA).
Breyite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₃Si₃O₉.
It crystallizes in the triclinic crystal system (space group P1). It is a member of the Margarosanite structural group.
Key properties: specific gravity 3.072; Vitreous luster.
IMA symbol Byi, IMA status: approved, named in 2018.
The second most abundant mineral inclusion after ferropericlase in diamonds of super- deep origin; only found in super-deep diamonds.
It is found associated with Diamond, ferropericlase, CaTiO3 perovskite, β-Ca2SiO4 larnite, titanite-structured CaSi2O5, ringwoodite.
Previously known as CaSiO3-walstromite. Honors the German mineralogist, petrologist, and geochemist Gerhard P. Brey (b. 1947), Professor of Mineralogy, Institute of Geosciences.