Nepheline /(nĕf"ē̇*lĭn)/

Neph·e·line

Nepheline

n.
  1. A mineral occuring 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. (Min.)