Isolated crystal of the extremely rare complex oxide mineral zimbabweite from the type and only known locality worldwide: St Anns Mine, Mwami, Karoi District, Mashonaland West, Zimbabwe. Specimen analyzed by Russian mineralogist Mikhail Murashko. — Photo: David Hospital · CC BY-SA 4.0
Zimbabweite
A yellow-brown lead-arsenic niobate-tantalate — an arsenite notable for its niobium content.
Intro adapted from Wikipedia (CC BY-SA).
Zimbabweite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Na(Pb,Na,K)₂(Ta,Nb,Ti)₄As₄O₁₈.
It crystallizes in the orthorhombic crystal system (space group Ccmb).
Key properties: Mohs hardness 5–5.5; specific gravity 6.2; White streak; Adamantine luster; optically biaxial.
IMA symbol Zbb, IMA status: approved, named in 1984.
Found in a hydrothermally altered kaolinized zone of a complex rare-metal and fluorine-rich granite pegmatite.
It is found associated with Kaolinite.
The name refers to Zimbabwe, the country where it was first found.