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Formula: (Mn,☐)TaTa2O8
Multiple oxide, wodginite group
Crystal System: Monoclinic
Specific gravity: 7.61 measured, 7.87 calculated
Hardness: 5 to 5½
Streak: Yellowish tan
Colour: Orange-red to deep red
Environments
Localities
The type locality is the Emmons Quarry, Uncle Tom Mountain, Greenwood, Oxford County, Maine, USA. The
pegmatite is complexly zoned with a wall zone comprising
K-feldspar, quartz,
almandine and schorl. The
intermediate zones comprise K-feldspar,
quartz, muscovite and altered
spodumene. A quartz-rich core is
present but is poorly exposed
(CM 56.543-553 2018).
Tantalowodginite occurs in the pegmatite core as
primary anhedral masses to 12 cm and rarely as crystals to 1 cm
in miarolitic cavities. Tantalite-(Mn) crystallised early, then as
fractionation continued tantalowodginite became the predominant phase and finally
columbite-group minerals
(R&M 94.2.186-187).
In the core margin complex, larger tantalowodginite crystals occur. Smaller tantalowodginite crystals
rimmed with columbite-tantalite are
found in small cavities in muscovite masses. Blocky tantalowodginite
with columbite overgrowths occurs next to the pockets in small interstitial
spaces. More complex crystals occur in pockets and in massive quartz around
pockets. These complex crystals have orange-red tantalowodginite cores and black
wodginite rims
(R&M 94.6.516).
Associated Minerals include wodginite,
schorl,
quartz, muscovite,
K-feldspar, fluorapatite,
columbite-(Mn) and almandine
(Mindat).
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