Naujakasite Locality: Naujakasik (Naajakasik), Tunugdliarfik Firth (Eriksfjord), Ilimaussaq complex , Narsaq , Kitaa (West Greenland) Province, Greenland ( Locality at mindat.org ) A sharp 1.4 cm crystal perched on matrix is the predominant feature here, but on the backside there is a cleaved-in-half partial crystal measuring a whopping 3 cm across, as well! This is an extremely rare species from the type locality, and this should be considered an excellent crystal. 4 x 3 x 3 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Naujakasite
Naujakasite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₆Fe²⁺Al₄Si₈O₂₆.
It crystallizes in the monoclinic crystal system (space group C2/m).
Key properties: Mohs hardness 2–3; specific gravity 2.62; Pearly on {001} luster; optically biaxial.
IMA symbol Nj, grandfathered status — known before the IMA’s founding, named in 1933.
Found in an alkalic intrusion.
It is found associated with Arfvedsonite, sodalite, steenstrupine, analcime.
The name is derived from the locality of original discovery, Naujakasik, Greenland.