Nepheline \Neph"e*line\, Nephelite \Neph"e*lite\, n. [gr. ? cloud: cf. F. n['e]ph['e]line. Cf. Nebula.]

(Min.) A mineral occuring at Vesuvius, in glassy agonal 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.

Source: Webster's Revised Unabridged Dictionary (1913)