Chaldean architecture circa 2000 B.C. featured columns covered in mosaics, with small cones of clay embedded in the structure of the column. Mosaic panels from circa 2600 to 2400 B.C. were excavated from a grave in the Royal Cemetery at Ur, the ancient Sumerian city.
Excavation reveals that by the 4th century B.C., the floors of well-to-do Greeks in Olynthus are covered in elaborate mosaics that use natural pebbles. During the next century, Greek mosaicists developed a technique of using small cubes cut from stone and fragments of colored glass, or “tesserae.”
Greek craftsman brought mosaics to Rome, where it was used widely for the flooring of villas. Mosaic materials used in the Roman era include stone, enamel, glass paste, marble, terracotta, mother of pearl and shells.
The use of “emblema” was popular in Hellenistic and Roman mosaics. The emblema was the central portion of the mosaic, often featuring figurative representations of people, animals or other objects.
From the 4th century A.D., the art form took a new turn with the use of mosaics by Christians to decorate the walls of churches rather than the floors. Byzantine rulers decorated the holy buildings of Ravenna with glittering mosaics, establishing the medium's association with Christian rule in the Roman empire.