Yellow crystals of the rare mineral shafranovskite associated to pink cubic villiaumite from the type locality for shafranovskite: Rasvumtchorr, Khibiny, Kola, Russian Federation. — Photo: David Hospital · CC BY-SA 4.0
Shafranovskite
Shafranovskite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₃K₂(Mn,Fe,Na)₄[Si₉(O,OH)₂₇](OH)₂·nH₂O.
It crystallizes in the hexagonal crystal system (space group P31c).
Key properties: Mohs hardness 2–3; specific gravity 2.76–2.78; Vitreous luster; optically uniaxial.
IMA symbol Sfn, IMA status: approved, named in 1981.
Produced by late-stage crystallization of alkalic nepheline syenite magmas in pegmatites in differentiated alkalic massifs.
It is found associated with Thermonatrite, natrophosphate, nacaphite, olympite, sidorenkite, aegirine, villiaumite, phosinaite, rasvumite.
The mineral was named to honor Professor Ilarion Ilarionovich Shafranovskii (1907-1994), mineralogist and crystallographer at the Mining Institute, St. Petersburg, Russia.