Kushiroite
A rare pyroxene representing the Calcium-Tschermak component — the fully aluminium-substituted member.
Intro adapted from Wikipedia (CC BY-SA).
Kushiroite is an IMA-recognized mineral species in the silicate class, with the chemical formula CaAlAlSiO₆.
It crystallizes in the monoclinic crystal system (space group C2/c). It is a member of the Pyroxene structural group.
Key properties: specific gravity 3.44.
IMA symbol Ks, IMA status: approved, named in 2008.
Found in a refractory inclusion in a CH group carbonaceous chondrite meteorite, perhaps formed by metastable crystallization from refractory melts in the solar nebula.
It is found associated with Grossite (ALH 85085); addibischoffite, hibonite, perovskite, Ti-kushiroite, spinel, melilite, anorthite, FeNi-metal (Acfer 214).
The mineral was named to honor Ikuo Kushiro, Professor Emeritus, University of Tokyo, Japan, for his seminal contributions to experimental petrology and mineralogy.