Wodginite

wodginite

tantalite

cassiterite

tapiolite

Images

Formula: Mn2+Sn4+Ta2O8
Multiple oxide containing tantalum, manganese-bearing mineral, wodginite group, columbite supergroup
Crystal System: Monoclinic
Specific gravity: 7.19 to 7.36 measured
Hardness: 5½
Streak: Brown
Colour: Red-brown, dark brown to black
Environments

Pegmatites

Wodginite is widely distributed in complex zoned tantalum-bearing pegmatites in amphibolite (Mindat, Dana).

Localities

One of two co-type localities is the Wodgina Tantalite Mine, Wodgina, Abydos Station, Port Hedland Shire, Western Australia. Here wodginite occurs in a matrix of albite, quartz and muscovite, associated with tantalite (AM 48.1417, Dana, HOM).
The Wodgina mainlode pegmatite is an albite pegmatite that was intruded into greenstone. It can be subdivided into 6 units:
(1) A cleavelandite layer of coarse bladed albite with tantalum minerals, spessartine and minor quartz and muscovite
(2) An aplitic layer of albite-quartz-muscovite with occasional coarse-grained masses of microcline
(3) An albite-quartz-microcline layer of medium to coarse-grained texture
(4) A quartz core as isolated grey quartz masses
(5) A sugary albite unit of albite, quartz and muscovite
(6) A lithium-mica replacement unit composed of lithium-bearing micas and albite
The units that included wodginite were the cleavelandite layer (1) and the sugary albite layer (5).
On nearby Mt Cassiterite and Mt Tinstone is a group of albite-spodumene pegmatites where the main economic tantalum ore minerals are wodginite and also cassiterite with abundant wodginite inclusions, and minor amounts of tapiolite, columbite-(Mn), tantalite-(Mn) and microlite (R&M 96.3.264-269).

The second of the two type localities is the Tanco Mine, Bernic Lake, Lac-du-Bonnet area, Manitoba, Canada, where wodginite occurs as the chief ore mineral in a major tantalum ore body in a complex zoned pegmatite in amphibolite. Associated minerals include microcline, albite, lepidolite, microlite, tantalite, cassiterite and tapiolite (Dana, HOM). The wodginite occurs as small, black grains up to about ten millimeters in diameter, containing inclusions of feldspar and/or mica. Additional minerals found in the pegmatite include quartz, lithium micas, spodumene, pollucite, amblygonite, beryl, lithiophilite, apatite, tourmaline, rhodochrosite and tantalite (AM 48.1417).
The assemblages of minerals in the pegmatite were deposited in succession from petalite + quartz to spodumene + quartz to eucryptite + quartz (R&M 92.2.153).

At the Jabuti claim, São Geraldo do Baixio, Minas Gerais, Brazil, wodginite occurs in large brilliant crystals sometimes epitaxially intergrown with cassiterite (Dana).

At the Emmons Quarry, Uncle Tom Mountain, Greenwood, Oxford County, Maine, USA, the pegmatite is a highly evolved boron-lithium-cesium-tantalum enriched pegmatite. Wodginite has been found only as rims on tantalowodginite (R&M 94.6.517).

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