Mosaic tiles are small pieces of tile that are held together in a sheet. Mosaics can come in many different shapes and be made out of glass, metal, stone, real pebbles, porcelain and more.Mosaics are often used as floor and wall decoration, and were particularly popular in the Ancient Roman world. Mosaic today includes not just murals and pavements, but also artwork, hobby crafts, and industrial and construction forms. Mosaics have a long history, starting in Mesopotamia in the 3rd millennium BC.