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Formula: Fe2+Ta2O6
One of the tantalite minerals. Multiple oxide,
columbite group, orthorhombic
paramorph of tetragonal
tapiolite-(Fe),
forms a series with tantalite-(Mn) and with
columbite-(Fe),
tantalum-bearing mineral
Crystal System: Orthorhombic
Specific gravity: 6.65 to 7.95 measured
Hardness: 6 - 6½
Streak: Black-brown
Colour: Brownish black, black
Solubility: Insoluble in hydrochloric and nitric acid; slightly soluble in sulphuric acid
Magnetism: Paramagnetic
Environments:
Tantalite-(Fe) is an accessory mineral in granite
pegmatites
(Webmin).
Localities
At the Lipovsk pegmatite field, Rezhevsky District, Sverdlovsk Oblast, Russia, intergrowths of
tantalite-(Mg), tantalite-(Fe),
columbite-(Fe) and uranium-bearing
microlite form rims on
tantalite-(Mn)
crystals in
andesine-calcite
nests in a deeply desilicated granite
pegmatite which crosscuts
serpentinite near its contact with
marble. Other associated minerals include
dravite-uvite,
chrysoberyl, phlogopite,
magnesio-hornblende to
edenite,
cordierite, phenakite and
clinochlore
(Minrec 35.4.356-357).
The type locality is Upper Bear Gulch, Tinton Pegmatite Mining District, Lawrence county, South Dakota, USA.
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