Nosean crystal, top view. Diameter: 0,5mm - Locality: Wannenköpfe, Ochtendung, Eifel region, Germany — Photo: Fred Kruijen · CC BY-SA 3.0 nl
Nosean
A sulfate-bearing sodalite-group feldspathoid — isometric crystals from white through blue to brown.
Intro adapted from Wikipedia (CC BY-SA).
Nosean is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₈(Si₆Al₆)O₂₄(SO₄)·H₂O.
It crystallizes in the cubic crystal system (space group P-43m). It is a member of the Cancrinite-sodalite, Sodalite structural group.
Key properties: Mohs hardness 5.5; specific gravity 2.3–2.4; typically blue or gray or white or brown or yellow; white streak; Vitreous luster.
IMA symbol Nsn, grandfathered status — known before the IMA’s founding, named in 1815.
Found in silica-deficient alkalic volcanic rocks, principally phonolites.
It is found associated with Sanidine, mica, leucite, magnetite, ilmenite, titanite, zircon.
The name commemorates Karl Wilhelm Nose (1753?{1835), German mineralogist, of Brunswick (now Lower Saxony), Germany.
Collections: Collector Favorites.