Vinogradovite on aegirine - Namibia, Windhoek, Aris Quarries - 1 mm. Photos from tomeikminerals.com can be used under a Creative Commons Licenese 4.0 CC-BY, as explained in: https://www.tomeikminerals.com/about-me . — Photo: Henk Smeets - Tomeik Minerals · CC BY 4.0
Vinogradovite
Vinogradovite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₄Ti₄(Si₂O₆)₂[(Si,Al)₄O₁₀]O₄·(H₂O,Na,K)₃.
It crystallizes in the monoclinic crystal system (space group C2/c).
Key properties: Mohs hardness 4; specific gravity 2.85–2.97; Vitreous luster; optically biaxial.
IMA symbol Vgd, grandfathered status — known before the IMA’s founding, named in 1956.
A late-stage hydrothermal mineral in cavities and veins, and replacing titanium-bearing minerals, in alkalic pegmatites in differentiated alkalic massifs (Kola Peninsula, Russia).
It is found associated with Lorenzenite, lamprophyllite, catapleiite, neptunite, labuntsovite, titanite, calcite.
In honor of Academician Aleksander Pavlovich Vinogradov (1895–1975), Russian geochemist, Director of the Vernadsky Institute of Geochemistry and Analytical Chemistry, Academy of Sciences, Moscow.