What is "phonolite"

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.

a kind of volcanic rock that rings when struck, c.1830, literally "sounding stone," from phono- + -lite. Based on German klingstein.

n. (context mineralogy English) a light-coloured rock of volcanic origin composed mostly of alkali feldspars

Phonolite is an uncommon extrusive igneous rock, volcanic rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic (fine-grain) to porphyritic (mixed fine- and coarse-grain).

The name phonolite comes from the Greek meaning "sounding stone" because of the metallic sound it produces if an unfractured plate is hit; hence the English name clinkstone.