The man have been used the clay from the Stone Age to innumerable usages, becoming away by supplementing part living daily: it was used to make bricks and plasters, mould statues and objects of cult, tools from work, stoves and crockery. This material, fragile because it breaks up, but indeteriorabile in time, is the more found in the archaeological sites, so to assume the role of "leader material " for study and dating of the cultures preceding the writing invention.