This name is applied to any musical instrument made of stone that produces a ringing sound when hit.
There are a surprising number of them around the world in places as far apart as Togo, Iceland and Venezuela. The Chinese ch’ing is a set of 16 L-shaped tuned stone slabs, which are suspended in a large frame and struck on their long side with wooden mallets or padded sticks.
The word is often applied to a specific example, the Vietnamese dan da, a set of resonant stones. A set in Ho Chi Minh City and another now in Paris can lay claim to be the oldest extant music instruments in the world, from 6,000 years ago. The stones were found in 1949 by Georges Condominas in a village in the central highlands of Vietnam. They were quarried from a place nearby where the rock is made of petrified wood and were chipped and shaped to tune them to a perfect pentatonic scale. They can still be played, by hitting them with wooden mallets, to make a sort of hugely antique stone marimba.
This is another example:
That morning [Evelyn] Glennie had received a gramorimba, a Swiss-made lithophone, that she has been asked to experiment with for the next six months.
The he Santa Fe New Mexican, 8 Oct. 2004.