Pebble washed exterior terrazzo is comprised of small rounded stones, also known as river pebbles or gravel, of different colours and sizes, which gives the typical name washed gravel. It is a composite flooring of aggregates, pebbles or river gravel (of different granulometries) and cement, which is compacted and leaves a raised relief in the face layer. This flooring is very commonly used in both public and private terraces, as well as in gardens and close to swimming pools, for a classical finish. Due to its high resistance and low cost, terrazzo in general is the most commonly used material for indoor and outdoor pavements. Terrazzo flooring began to be used in Venice in the middle of the XV century, to take advantage of the leftover pieces from the construction of marble floors. The word terrazzo derives from the Italian word "Terrazza" – it in turn derived from the Latin "terracĕus" terra (ground), for initially these soils were used to pave the terraces surrounding the houses of the construction workers. In its original composition, the soil of terrazzo consisted simply of a clay base on which chips of marble ,granite and pebbles were laid. Subsequently these pebbles were polished or rubbed to achieve a more comfortable Surface.