Namansilite Locality: Woods Mine, Tamworth, Darling Co., New South Wales, Australia Description: Purple namansilite inclusions within granular quartz. Specimen is about 100mm across — Photo: Matthew Goodwin · CC BY 3.0
Namansilite
Namansilite is an IMA-recognized mineral species in the silicate class, with the chemical formula NaMn³⁺Si₂O₆.
It crystallizes in the monoclinic crystal system (space group C2/c).
Key properties: Mohs hardness 6; specific gravity 3.51; Brownish violet streak; Adamantine; vitreous to pearly luster; optically biaxial.
IMA symbol Nms, IMA status: approved, named in 1989.
Found in low-grade metamorphosed and highly oxidized Mn, Na-rich sediments.
It is found associated with Taikanite, pectolite, manganoan amphiboles, manganoan orthoclase, manganoan vermiculite (Irnimi deposit, Russia); pectolite, potassic feldspar, braunite.
The name refers to sodium, NAtrium; MANganese; and SILicon in the formula.