A lithophone is a musical instrument consisting of a rock or pieces of rock which are struck to produce musical notes.[1] Notes may be sounded in combination (producing harmony) or in succession (melody). It is an idiophone comparable to instruments such as the glockenspiel, vibraphone, xylophone and marimba.
In the Hornbostel-Sachs classification system, lithophones are designated as '111.22' – directly-struck percussion plaques.