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