Monster stone is a type of igneous rock that is formed through the cooling and solidification of volcanic magma or lava. Monster stone that has the hardness the same with andesite stone is generated from lava that has been buried in the beneath the surface of earth's crust in long time.
Monster has a very classic shape with small holes on the stone surface. In general, small holes dimension in the stone is about 5-10 mm and sometimes they penetrate up to the surface behind him.