Abstract: The method and apparatus treat a surface of natural rock or artificial stone-like material to give to this surface an attractive finish. A high temperature jet of plasma and a high speed jet of cooling fluid are projected onto the surface to be treated. The two jets are moved on the surface at a given speed with the jet of cooling fluid following the plasma jet. The speed of movement is selected so that the high temperature plasma jet heats only a thin superficial layer of rock or stone-like material. As the jet of cooling fluid follows the jet of plasma, it suddenly cools the thin superficial layer just heated by the plasma jet to cause a thermal shock which bursts particles of rock or stone-like material at the surface thereof, and blows these particles off the rock surface.