The technique of Opus Sectile is mentioned for the first time by Vitruvius, while Pliny the Elder dates its invention to the fourth century BC. It is a simple process that requires great precision: the stone is in fact cut into thin slabs with predetermined shapes called sectilia, which are then placed next to and fixed with the mortar to compose the desired decoration. The result is a panel that is perfectly flat and regular to the touch, shiny and colorful thanks to the different orientation of the veins and the use of various qualities of marble; for a greater chromatic richness sometimes also elements of terracotta or glass paste were inserted L.Lazzarini