Srebrodolskite

srebrodolskite

brownmillerite

jasmundite

fluorellestadite

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Formula: Ca2Fe3+2O5
Oxide, perovskite group, forms a series with brownmillerite
Specific gravity:
Hardness: 5½
Streak: Greyish brown
Colour: Black
Solubility: Soluble in hydrochloric acid
Environments

Coal-seam fires

Srebrodolskite occurs in calcined ankerite in petrified wood baked by burning coal heaps (Webmin).

Localities

At the North-Bohemian Brown Coal Basin, Czech Republic, srebrodolskite forms uneven aggregates and grains up to 2 mm between melilite and larnite crystals, and the more Si-rich variety occurs as grains up to 150 μm in size, associated with magnesioferrite, perovskite, and barioferrite in a Ca-Fe-rich metamorphic rock (AM 91.216-224).

At The Bellerberg volcano, Germany, srebrodolskite occurs in leucite tephrite lava at contacts between lava and calcium-rich xenoliths, associated with sanidine, clinopyroxene, pyrrhotite, thomsonite, ettringite, willhendersonite, gismondine, jasmundite, mayenite, bellbergite, calcic olivine and portlandite (HOM).

At the type locality, Kopeisk, Chelyabinsk coal basin, Chelyabinsk Oblast, Russia, srebrodolskite occurs in petrified wood baked by burning coal in mines. The baked petrified wood consists of an anhydrite shell enclosing earthy masses of portlandite, carbonates and aggregates of srebrodolskite in grains generally less than 0.1 mm across. Srebodolskite is derived from the calcining of ankerite (AM 71.1279-1280). Associated minerals include portlandite, fluorellestadite, periclase, spurrite, larnite, magnesioferrite, hematite and anhydrite (HOM ).

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