Tantalowodginite

tantalowodginite

columbite

fluorapatite

wodginite

Images

Formula: (Mn,☐)TaTa2O8
Multiple oxide, wodginite group
Specific gravity: 7.61
Hardness: 5 to 5½
Streak: Yellowish tan
Colour: Orange-red to deep red
Environments

Pegmatites

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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