Roaldite
A rare iron-nickel nitride described in 1981 from Australia's Youndegin meteorite.
Intro adapted from Wikipedia (CC BY-SA).
Roaldite is an IMA-recognized mineral species in the native element class, with the chemical formula (Fe,Ni)₄N.
It crystallizes in the cubic crystal system (space group P-43m).
Key properties: Mohs hardness 6; specific gravity 7.21; optically isotropic.
IMA symbol Roa, IMA status: approved, named in 1980.
Found as a rare accessory mineral in iron-nickel meteorites, probably formed by diffusion of nitrogen.
It is found associated with Kamacite, cohenite, schreibersite, carlsbergite, daubreelite.
The mineral was named to honor Roald Norbach Nielsen (1928–), Danish electron microprobe analyst, of the Department of Metallurgy, Danish Technical Institute, Lyngby, Denmark.