Phonolite

from 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]
    

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