Very small single crystal of the extremely rare mineral Vladimirivanovite from the type locality and only one of the two known localities worldwide: Tultui Lazurite Deposit, Malaya Bystraya River, Slyudyanka, Irkutsk Oblast, Russian Federation. — Photo: David Hospital · CC BY-SA 4.0
Vladimirivanovite
Vladimirivanovite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₆Ca₂[Al₆Si₆O₂₄](SO₄,S₃,S₂,Cl)₂·H₂O.
It crystallizes in the orthorhombic crystal system. It is a member of the Cancrinite-sodalite, Sodalite structural group.
Key properties: Mohs hardness 5–5.5; specific gravity 2.48; Blue streak; Vitreous to greasy luster; optically biaxial.
IMA symbol Vla, IMA status: approved, named in 2010.
Found in highly metamorphosed rocks of granulite facies at the contacts of dolomitic marbles with granites.
It is found associated with Lazurite, calcite, afhganite, tounkite, phlogopite, marialite.
The mineral was named to honor Russian mineralogist and geochemist Vladimir Georgievich Ivanov (1947-2002).