Formula: Sb3+TaO4
Tantalate, cervantite group, antimony-bearing mineral, forms a series with stibiocolumbite
Crystal System: Orthorhombic
Specific gravity: 5.98 to 7.34 measured, 7.58 calculated (7.391 calculated for the sample from China, presumably for the empirical formula)
Hardness: 5½ to 6
Streak: Light yellow, yellow-brown
Colour: Dark brown to light yellowish brown, reddish yellow, reddish brown, greenish yellow
Common impurities: Nb

Placer deposits

Stibiotantalite is an uncommon accessory mineral in complex granite pegmatites (HOM).


At the type locality, the Greenbushes Sn placers, Greenbushes Tinfield, Bridgetown-Greenbushes Shire, Western Australia, stibiotantalite has been found in a waterworn pebble associated with tantalite (Mindat).

At the Nanyangshan 363 deposit, Nanyangshan pegmatite field, Lushi County, Sanmenxia, Henan, China, a sample of stibiotantalite was collected from the rare-metal bearing lithium - cesium - tantalum pegmatite.
The stibiotantalite occurs in an albite-rich unit of the pegmatite where it is associated with columbite-(Mn), tantalite-(Mn), albite, quartz, elbaite, spodumene, and the lithium-micas polylithionite, trilithionite, luanshiweiite and fluorluanshiweiite. The stibiotantalite is commonly replaced by oxystibiomicrolite, oxycalcioroméite, stibnite, bismuthinite and cervantite; oxycalciomicrolite and oxycalcioroméite are the most common replacement products.
The stibiotantalite forms as prismatic, pale to dark grey crystals with maximum dimensions of 5 cm in length and 2 cm in width (CJMP 61.965-977).

At Varuträsk, Skellefteå, Västerbotten County, Sweden, stibiotantalite is associated with antimony, stibarsen, microlite, oxystibiomicrolite, lithiophilite, alkali-beryl, cassiterite and columbitetantalite (HOM).

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