Nepheline
Nepheline (nef"e*lin) , noun
[Greek nefe`lh cloud: compare French néphéline. Compare Nebula.]
(Mineralogy) A mineral occurring at Vesuvius, in glassy hexagonal crystals; also elsewhere, in grayish or greenish masses having a greasy luster, as the variety elaeolite. It is a silicate of aluminia, soda, and potash.
Also: Nephelite