Brown crystals of the very rare Ba-Zr silicate mineral komkovite from the type and only known locality worldwide in Russia (Vuoriyarvi Massif, Northern Karelia, Murmansk Oblast, Russian Federation). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Komkovite
Komkovite is an IMA-recognized mineral species in the silicate class, with the chemical formula BaZrSi₃O₉·3H₂O.
It crystallizes in the hexagonal crystal system (space group R32).
Key properties: Mohs hardness 3–4; specific gravity 3.31; Light brown streak; Vitreous luster; optically uniaxial.
IMA symbol Kkv, IMA status: approved, named in 1988.
Apparently altering from catapleiite, in dolomitic veinlets cutting metasomatically altered pyroxenites, in a carbonatite.
It is found associated with Dolomite, strontianite, phlogopite, barite, georgechaoite, pyrite.
The mineral was named to honor Russian mineralogist and crystallographer Aleksandr Ivanovich Komkov (1926–1987), Karpinskii All-Union Research Institute of Geology, St. Petersburg, Russia.