Ancient glass sculpture is very rare. This is one of the earliest known glass portraits. It probably shows the head of Amenhotep II, who was ruler of Egypt about 60 years before Tutankhamen. The craft of glassmaking may have been introduced into Egypt during Amenhotep's reign. The head was carefully sculpted, probably with the simplest of tools and considerable effort on the part of the craftsman. Cast in blue glass, the sculpture is now tan in color due to its long burial. Several royal portrait heads in glass are known. They were probably made as parts of composite figures designed to incorporate other materials, such as gold, ivory, and wood.