The mosaic is made up of pebbles in many colors. A circular area of the mosaic is missing, but authorities say enough fragments have been found to reconstruct a large part. Archaeologists have dated the mosaic to the last quarter of the fourth century B.C., consistent with their belief the grave contains the remains of a contemporary of Alexander the Great — most likely a relative or one of Alexander‘s generals. Alexander, who died in 323 B.C., is believed to have been buried in Egypt — but his tomb hasn‘t been found.