from Real Clear Science

Where Did Rome’s Famous ‘Alexandrian’ Glass Come From

By Ross Pomeroy

Two thousand years ago, the Roman Empire was cranking out glassware unsurpassed in intricacy, beauty, or design, with skill and efficiency that wouldn’t be topped until the advent of modern industry in the 18th century. Large production operations scattered across the empire combined sand and nitrate in kilns reaching 1100 degrees Fahrenheit, creating giant gobs of glass that were then cooled and distributed in huge hunks far and wide. Glassworkers would then purchase this solid glass, re-melt it, and craft it into vessels and other wares.

Various types of glass were manufactured, but the most prized may have been Alexandrian glass, described by one ancient writer as “colourless or transparent, as closely as possible resembling rock crystal.” Glassmakers achieved this feat by oxidizing the sand’s iron from blue Fe2+ to pale Fe3+ by adding antimony oxide. The glass offered a blank slate for decoration and was sought after for serving vessels. The glass’ name hints that it hailed from Egypt when it was a Roman province (the capital was Alexandria), but its precise origin has remained elusive to historians.

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