The archaeological ruins of Piramesses (called Qantir, for the modern town nearby) were found in the 19th century by Mahmoud Hamza and have been excavated since 1984 by Edgar B. Pusch with the support of the Roemer und Pelizaeus-Museum, Hildesheim, Germany. Puschs excavations reveal that the site covered an area of nearly 30 square kilometers and includes remains of temples, workers houses, horse stables, and specialist workshops for making arms and chariots. Historical records describing Piramesses (literally, the Home of Ramesses) remark on the magnificence of his main temple, inlaid with gold, silver, lapis lazuli, and turquoise. Piramesses was located in the Delta region of the Nile, and was noted for its trade connections because of its proximity to the river. Puschs excavations identified a workshop, which apparently produced faience, glass beads, and glass ingots for making glass vessels, but not the glass vessels themselves.
The Qantir workshop illustrates the early steps of the process of glass vessel casting, preparing glass to be shaped into molds. Glass fabrication illustrated at Qantir was done in a multi-step process. First, the workers ground quartz-rich sand into a fine powder and melted it in ceramic vessels lined with lime and constructed with a narrow opening. These vessels were heated to a temperature of between 900 and 950 degrees Centigrade. Once cooled, the raw glass was popped out of the jars and crushed again, then washed to remove the impurities. Next, the refined glass powder was mixed with coloring agents and poured into cylindrical crucibles. These crucibles were heated to between 1000-1100 degrees C, producing intensively colored disk-shaped glass ingots. These monochromatic ingots were then shipped to artisans who used the ingots to make polychrome glass vessels, faience, and glass slips. Ingot colors produced at Piramesses included clear, red, cobalt blue and a transparent purple color.
To Amarna and Beyond
So what happened to the ingots after their production? Likely they were forwarded to artisans both in and outside of Egypt. Evidence for the importance of the international trade in glass ingots has been found at the Late Bronze Age Uluburun shipwreck, discovered off the coast of Kas in southern Turkey. Uluburuns wreck contained 175 disk-shaped glass ingots, apparently on their way to artist workshops when the boat sank in 1306 BC. The ingots at Uluburun were of deep blue (mixed with cobalt), turquoise (mixed with copper), and a shade of lavender; their shape is similar to the crucibles found at Qantir-Piramesses.
See the Illustrated Guide to Glass Making for more information.
Rehren, Thilo and Edgar B. Pusch 2005 Late Bronze Age Glass Production at Qantir-Piramesses, Egypt. Science 308:1756-1758.