Yellow crystal aggregates of the very rare Na-Al-V oxide mineral vanalite from the TL (Kurumsak, Aksumbe, Turkistan Region, Kazakhstan) and only one of the two known localities worldwide, in a dark contrasting matrix. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Vanalite
Vanalite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula NaAl₈V₁₀O₃₈·30H₂O.
It crystallizes in the monoclinic crystal system.
Key properties: specific gravity 2.3–2.4; Waxy to vitreous luster; optically biaxial.
IMA symbol Vnl, IMA status: approved, named in 1962.
Incrusting joints and cavities in weathered shales.
It is found associated with Steigerite, hewettite, delvauxite, satpaevite, gypsum, halloysite, montmorillonite, other clay minerals.
The name refers to VANadium and ALuminum in the composition.