Formula: (Ce,Ca,Fe,Th)(Ti,Nb)2(O,OH)6
Multiple oxide containing niobium or titanium, aeschynite group,
forms series with
nioboaeschynite-(Ce) and with
aeschynite-(Y)
(Mindat ).
Specific gravity: 5.19
Hardness: 5 to 6
Streak: Nearly black to brown
Colour: Black, brown, light brown to yellow
Common impurities: REE,Sn
Environments
Plutonic igneous environments
Pegmatites
Carbonatites
Placer deposits
Metamorphic environments
Aeschynite-(Ce) occurs in nepheline syenite, in
granite pegmatites and in carbonatites in alkaline rocks; it is also a detrital mineral
in placers. It is often metamict. Associated minerals include feldspar,
zircon, samarskite,
columbite, allanite and
titanite (HOM, Mindat).
Localities
The type locality is the Gadolinite Pit, Chelyabinsk Oblast, Russia.
At the Dark Star claim, Ravalli county, Montana, USA, aeschynite-(Ce) occurs in carbonatite rocks associated with
allanite, apatite,
monazite-(Ce), fersmite,
magnetite, pyrite and
columbite (Dana).
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