Gazeevite
Gazeevite is an IMA-recognized mineral species in the silicate class, with the chemical formula BaCa₆(SiO₄)₂(SO₄)₂O.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Zadovite structural group.
Key properties: Mohs hardness 4.5; specific gravity 3.39; White streak; Vitreous luster; optically uniaxial.
IMA symbol Gaz, IMA status: approved, named in 2015.
A high-temperature reaction product in carbonate-silicate xenoliths in rhyodacite (Georgia) or in pyrometamorphic rocks in association with volcanism or natural combustion (Israel).
It is found associated with Larnite, fluorellestadite-fluorapatite, srebrodolskite-brownmillerite, minerals of the mayenite supergroup.
The mineral was named to honor Viktor Magalimovich Gazeev (b. 1954), research staff of the Institute of Geology of Ore Deposits, Petrography.