nephelite
Neph"e*line, Neph"e*lite, n. Etym: [gr. néphéline. Cf. Nebula.] (Min.) Defn: A mineral occuring at Vesuvius, in glassy agonal crystals; also elsewhere, in grayish or greenish masses having a greasy luster, as the variety elæolite. It is a silicate of aluminia, soda, and potash.