Shirokshinite
Shirokshinite is an IMA-recognized mineral species in the silicate class, with the chemical formula K(Mg₂Na)Si₄O₁₀F₂.
It crystallizes in the monoclinic crystal system (space group C2/m).
Key properties: Mohs hardness 2.5; specific gravity 2.922; White streak; Vitreous to pearly luster; optically biaxial.
IMA symbol Shk, IMA status: approved, named in 2001.
A late hydrothermal mineral in cavities within a hyperalkaline pegmatite embedded in ristschorrite in an alkaline massif.
It is found associated with Microcline, kupletskite, aegirine, natrolite, lorenzenite, calcite, remondite-(Ce), donnayite-(Y), mckelveyite-(Y), galena.
The mineral was named to honor Russian geologist Nikolay Vasilievich Shirokshin (1809 - ?), a Captain of the Russian Mining Corps.