Srebrodolskite
Srebrodolskite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Ca₂Fe³⁺₂O₅.
It crystallizes in the orthorhombic crystal system (space group Pnma). It is a member of the Perovskite, Brownmillerite structural group.
Key properties: Mohs hardness 5.5; specific gravity 4.04; Grayish brown streak; Adamantine, metallic in aggregates luster; optically biaxial.
IMA symbol Sre, IMA status: approved, named in 1984.
Formed from calcined ankerite in petrified wood baked by burning coal heaps (Kopeysk, Russia); in leucite tephrite lava at contacts between lava and calcium-rich xenoliths (Bellerberg volcano, Germany).
It is found associated with Portlandite, fluorellestadite, lime, periclase, spurrite, larnite, magnesioferrite, hematite, anhydrite (Kopeysk, Russia); sanidine, clinopyroxene, pyrrhotite.
The mineral was named to honor Dr. Boris Ivanovich Srebrodol’skii (1927–), Russian-Ukrainian mineralogist, Institute of Geology and Geochemistry, Lvov, Ukraine.