Stone carving is an ancient activity where pieces of rough natural stone are shaped by the controlled removal of stone. Owing to the permanence of the material, evidence can be found that even the earliest societies indulged in some form of stone work. Work carried out by paleolithic societies to create flint tools is more often referred to as knapping. Stone carving that is done to produce lettering is more often referred to as lettering. Stone carving differs from stone as in marble quarrying in that it is the act of shaping or incising the stone, whereas quarrying is the activity of acquiring useful stone, usually in blocks, from geological sources.