Researchers link ancient Egyptians to glass production

New excavations on the eastern Nile Delta show that ancient Egyptians had large-scale glass-making operations several hundred years earlier than researchers had believed, and the archeological remains provide the first solid evidence about how they did it, British and German researchers report today.

The glass factory at Piramesses, which probably began production around 1250 B.C. — about 100 years after the reign of King Tutankhamun — used a two-step process in which pulverized quartz was heated with plant ash in ceramic beer jars to form a crude solid.

Crushed again, the raw glass was heated to higher temperatures and colorized to form valuable ingots that were shipped to fabricators in Egypt and throughout the Mediterranean region, the team reports in the journal Science.

"For the first time, we can actually demonstrate that people made glass there and how they did it," said archeologist Thilo Rehren of University College, London, one of the paper's authors. "We're confirming what previously we could only guess about."

Glassmaking is thought to have originated in Mesopotamia — now Iraq and Syria — about 1550 B.C.

By 1250 B.C., the technology had become substantially better, although artisans could only produce opaque, colored glass used to make small items such as perfume containers, figurines and other decorative objects.

Researchers knew that craftsmen at several sites in Egypt were working with glass ingots and using them to fabricate objects of art. But most assumed the ingots were brought in from Mesopotamia or elsewhere.

A famous wrecked cargo vessel discovered off the Turkish coast of Ulu Burun in the 1980s carried 175 such ingots, and researchers had assumed that they were destined for Egypt.

The discovery reported today, however, strongly suggests that the ingots were manufactured in Egypt and bound for the Middle East, said glass expert Robert Brill of the Corning Museum of Glass in Corning, N.Y.

Many historians assumed that sand was used as a raw material for the glass, but the excavation reveals that the Egyptians used quartz pebbles that were laboriously pulverized.

Traces of the quartz grains remain in some of the crude glass they found.