Eitelite Locality: Westvaco mine, Green River formation, Sweetwater County, Wyoming, USA Dimensions: 3.5 cm x 1.4 cm x 1.1 cm Description: Eitelite is an extremely rare carbonate mineral species, found in masses of grains or smears at a very few locales. Interestingly it was named after the scientist who first made it in the lab, rather than a natural crystal or example. Thus, natural, large eitelite specimens are unprecedented, even more than with most rare species, and this surprise new find released at the 2012 Tucson show was a big surprise for those who collect the rarities. These attractive specimens seem to be true crystals of eitelite, though grown in conjoined, lamellar masses. The top may be a contacted termination, where it grew against a constricting matrix of the pocket. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Eitelite
Eitelite is an IMA-recognized mineral species in the carbonate class, with the chemical formula Na₂Mg(CO₃)₂.
It crystallizes in the hexagonal crystal system (space group R-3).
Key properties: Mohs hardness 3.5; specific gravity 2.737; Vitreous luster; optically uniaxial.
IMA symbol Eit, grandfathered status — known before the IMA’s founding, named in 1955.
An authigenic mineral in dolomitic shale and bituminous marlstone (Utah, USA); from an alkaline igneous pluton (Khibiny massif, Russia).
It is found associated with Reedmergnerite, leucosphenite, searlesite, crocidolite, shortite (Kermit Poulson No. 1 well, Utah, USA); trona, nahcolite, shortite.
The mineral was named to honor Wilhelm Hermann Julius Eitel (1891–1979), Director of the Institute of Silicate Research, University of Toledo, Toledo, Ohio, USA, who synthesized the compound.