Seifertite
One of the densest silica polymorphs — found only in shocked Martian and lunar meteorites.
Intro adapted from Wikipedia (CC BY-SA).
Seifertite is an IMA-recognized mineral species in the silicate class, with the chemical formula SiO₂.
It crystallizes in the orthorhombic crystal system (space group Pbcn).
Key properties: specific gravity 4.294.
IMA symbol Sft, IMA status: approved, named in 2004.
Formed by shock-induced solid-state transformation (> 35 GPa) of either tridymite or cristobalite in basaltic achondrite meteorites, presumably of Martian origin.
It is found associated with Stishovite, silica glass, unnamed monoclinic silica polymorph.
The mineral was named to honor Friedrich A. Seifert (b. 1941), founding Director of the Bayerisches Geoinstitut, Universität Bayreuth, Germany.