Meaning of phonolite

pho•no•lite

Pronunciation: (fōn'l-īt"), [key]
— n.
  1. a fine-grained volcanic rock composed chiefly of alkali feldspar and nepheline, some varieties of which split into pieces that ring on being struck.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.