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Formula: Na(Pb,Na,K)2(Ta,Nb,Ti)4As4O18
Arsenite-Tantalate,
also niobium- and titanium-
bearing mineral
Crystal System: Orthorhombic
Specific gravity: 6.20 measured, 6.16 calculated
Hardness: 5 to 5½
Streak: White
Colour: Yellow, yellow-brown
Luminescence: Not fluorescent under UV
Solubility: Insoluble in common acids and bases
Environments
Pegmatites
Hydrothermal environments
Although zimbabweite was approved in 1984, to date (October 2022) it has been reported only from the type
locality.
Localities
The type locality, St Anns Mine, Mwami, Karoi District, Mashonaland West, Zimbabwe, exploited one of several
lithium-cesium-tantalum
(LCT) pegmatites. The
albite-rich St. Anne’s
pegmatite has low concentrations of
lithium and was mined primarily for
beryl. The pegmatite is
contained within mica schists. The
zimbabweite was found as poorly developed yellow-brown crystals to 2 cm long and 1 cm wide in the hydrothermally
kaolinised pegmatite
and dump material
(R&M 97.4.383-386).
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