The Collaborative International Dictionary of English v.0.48:

Phonolite \Pho"no*lite\, n. [Phono- + -lite: cf. F. phonolithe.]
   (Min.)
   A compact, feldspathic, igneous rock containing nephelite,
   ha["u]ynite, etc. Thin slabs give a ringing sound when
   struck; -- called also clinkstone.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Clinkstone \Clink"stone`\ (?; 110), n. [Clink + stone; -- from
   its sonorousness.] (Min.)
   An igneous rock of feldspathic composition, lamellar in
   structure, and clinking under the hammer. See Phonolite.
   [1913 Webster]