Nierite
Natural silicon nitride (Si₃N₄) — an extremely rare mineral known from meteorites.
Intro adapted from Wikipedia (CC BY-SA).
Nierite is an IMA-recognized mineral species in the native element class, with the chemical formula Si₃N₄.
It crystallizes in the hexagonal crystal system (space group P31c).
Key properties: specific gravity 3.17; optically uniaxial.
IMA symbol Nr, IMA status: approved, named in 1994.
A very rare component of enstatite chondrite and chondrite meteorites, probably formed by exsolution during metamorphism.
It is found associated with Diamond, kamacite, perryite, schreibersite, troilite, spinel, chromite, hibonite, rutile.
The mineral was named to honor Alfred Otto Carl Nier (1912-1994), Professor of Chemistry at the University of Minnesota, Minneapolis, Minnesota, USA, a founder of mass spectroscopy.