What is "nephelite"

Nepheline \Neph"e*line\ (n[e^]f"[-e]*l[i^]n), Nephelite \Neph"e*lite\ (n[e^]f"[-e]*l[imac]t), n. [Gr. nefe`lh cloud: cf. F. n['e]ph['e]line. Cf. Nebula.] (Min.) A mineral occuring at Vesuvius, in glassy hexagonal crystals; also elsewhere, in grayish or greenish masses having a greasy luster, as the variety el[ae]olite. It is a silicate of aluminia, soda, and potash.

n. (synonym of nepheline English)

n. a whitish mineral consisting of sodium aluminum silicate or potassium aluminum silicate in crystalline form; used in the manufacture of ceramics and enamels [syn: nepheline]