Black spheres of kazakhstanite on matrix from the 5425 Bench, Gold Quarry Mine (Maggie Creek Subdistrict, Carlin Trend, Eureka Co., Nevada, USA). Field of view 4 mm. — Photo: Leon Hupperichs · CC BY-SA 3.0
Kazakhstanite
Kazakhstanite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Fe³⁺₅V⁴⁺₃V⁵⁺₁₂O₃₉(OH)₉·9H₂O.
It crystallizes in the monoclinic crystal system.
Key properties: Mohs hardness 2.5; specific gravity 3.4–3.6; Black, with slight brownish tint streak; Adamantine, dull in aggregates luster.
IMA symbol Kaz, IMA status: approved, named in 1988.
Found in thin veins or cementing breccia in the weathering zone of vanadiferous black shales (Kara-Tau Mountains, Kazakhstan); in a hydrothermal gold deposit (Gold Quarry mine, Nevada, USA).
It is found associated with Bokite (Kara-Tau Mountains, Kazakhstan); fervanite, schubnelite, hewettite, tyuyamunite, cacoxenite, variscite, fluellite (Gold Quarry mine, Nevada, USA).
The name refers to its occurrences in Kazakhstan.