Yegorovite
Yegorovite, ([Na4[Si4O8(OH)4]·7H2O]) is a silicate mineral found in a hyperalkaline pegmatite in the Lovozero Pluton at Mt. Kedykverpakhk in the Kola Peninsula of Russia. It was named in memory of Russian crystallographer Yurii Kavdievich Yegorov-Tismenko, and approved by the Commission on New Minerals and Mineral Names, International Mineralogical Association in 2008.
Intro adapted from Wikipedia (CC BY-SA).
Yegorovite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₄[Si₂O₄(OH)₂]₂·7H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/c).
Key properties: Mohs hardness 2; specific gravity 1.9; White streak; Vitreous luster; optically biaxial.
IMA symbol Yeg, IMA status: approved, named in 2008.
Late hydrothermal, low temperature paragenesis in peralkaline pegmatite.
It is found associated with Revdite, megacyclite, natrosilite, microcline, villiaumite.
The mineral was named to honor Russian crystallographer and crystal-chemist Yurii Kavdievich Yegorov-Tismenko (1938-2007), Faculty of Geology, Moscow State University.