Outstanding sharp marine green alvanite crystals from the type locality (Kurumsak, Karatau Range, Southern Kazakhstan Province, Kazakhstan) in a contrasting matrix. It has a rare chemical composition since it is a ino-vanadate. Alvanite has only been found in three close deposits worldwide. — Photo: David Hospital · CC BY-SA 4.0
Alvanite
Alvanite (IMA symbol: Alv) is a zinc nickel aluminium vanadate mineral with the chemical formula (Zn,Ni)Al4(V5+O3)2(OH)12·2H2O. It was originally discovered in the Karatau Mountains.
Intro adapted from Wikipedia (CC BY-SA).
Alvanite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Zn²⁺Al₄(V⁵⁺O₃)₂(OH)₁₂·2H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/n). It is a member of the Chalcoalumite structural group.
Key properties: Mohs hardness 3–3.5; specific gravity 2.49; White streak; Vitreous, pearly on cleavages luster; optically biaxial.
IMA symbol Alv, IMA status: approved, named in 1959.
Found in the oxidation zone of a vanadiferous clay-anthraxolite horizon.
It is found associated with Mica, roscoelite (?).
The name refers to ALuminum and VANadium in the composition.