“Man,” relates Roman historian Pliny, “discovered glass by accident.” Phoenician seafaring merchants, come ashore, found no stones at hand to support their cooking pots. So they propped them up on blocks of nitrum, a natural occurring salt, taken from their cargo. As the nitrum heated up, it melted into the sand, forming a strange liquid that flowed in streams – molten glass. Whether truth or legend, by about 2000 BC, Phoenician sea vessels were plying the Mediterranean coast laden with translucent glass bowls, flasks, and striped juglets.
Glass reached Rome when the Emperor Augustus imported Judaean, Syrian, and Egyptian slave master glassworkers. Eventually, due to Rome’s extensive road system and far reaching trade routes, their expertise spread to the farthest reaches of the Empire.
Core and rod work, a glass working technique that harks back to Ancient Egypt, features clay and straw cores attached to metal rods. Craftsmen either tailed liquid glass over the cores, or dipped them repeatedly into molten glass to build up volume. These vials, called unguentaria, were perfect for storing their herb-scented unguents or fragrant oils. Their thick walls, combined with elongated, slender necks, not only protected against evaporation, but also dispensed their contents drop by expensive drop. Besides, these unguentaria, which often featured cheerful zig-zag patterns in contrasting colors or adorned with delicate, winding coils of color, were beautiful to behold.
To produce cold cut glass, craftsmen approached blocks of glass as they did precious stones, creating facets through stone and gemstone cutting techniques. They produced cast glass, another traditional type, by pouring molten glass or fusing glass chips into single or interlocking molds. When their thick walled, sharp edged creations cooled, artisans lathed and polished them into smoothness. Then they added details, rims, handles, and bases.
Decorative techniques varied. Craftsmen sometimes rolled warm cast glass into narrow “snakes,” then bound them into multicolor logs. After slicing and fusing them, they created striking, intricately designed millefiori (million flowers) bowls, vases, and platters. Craftsmen gently distorted warmed glass in contrasting colors, much like making marble cake, to create varicolored glass vessels too. They also formed lace patterns, painstakingly twisting strips of colored glass with fine contrasting threads, then fusing them together to create striking, intricate designs.
The introduction of blown glass, Rome’s most innovative technique, allowed artisans more spontaneity and more creativity than traditional methods. Blowing air into a wad of molten glass through a blowpipe results in thinner and smoother walls, quicker results and lower costs. Now Rome’s middle and lower classes—even her slaves—could pour wine from glass beakers, light glass oil lamps, and dine on glass platters. At the public baths, attendants stored massage oil in glass flasks. Ladies stored their herbal lotions, fragrant oils, ocher cheek rouge, and mineral-based eye shadows in delicate glass vials.
Mold blowing, blowing glass into standardized molds, followed, allowing quick, mass production of standardized forms. Now, glass was cheap and expendable enough to use in amphorae, two handled narrow-necked storage jars, for transporting olive oil, dried fruits, grains, and other foodstuffs by land and sea.
Glassworkers, by the middle of the first century AD, were producing vast quantities of transparent, pale bluish-green tinted glass. Then colorless glass, prized for its similarity to rock crystal, became all the rage. Innovative decorative techniques, like lathe-cutting, cameo-carving, and engraving soon followed. Some engravers portrayed scenes from Greek mythology. Others mimicked precious metals, or even adorned their creations with gold leaf. By the second century CE, it is estimated that Rome was producing a hundred million glass items a year.
Over the next five centuries, Roman glass working techniques and styles swept not only the Mediterranean Basin, but also most of Europe. In art and industry, they still influence us today.
Roman glass, sand (silica and lime) fused with natrum, is impervious to the ravages of time – except for breakage, of course. Roman tomb excavations across Turkey, Sicily, Syria, and Lebanon, for example, often reveal glass vessels. Roman shipwrecks often yield, along with scores of broken fragments, scores of intact amphorae, bowls, and plates. Many of these finds boast characteristic iridescent blue-green or rainbow-hued patinas, often highly coveted by collectors.
Glass workers did not create these lovely hues and textures, however. They evolved through centuries of exposure to wind, weather, and mineral matter. These patinas, it turns out, are not permanent. Even today, exposure to water, sea spray, sweat, and detergents can affect their delicate finish, cautions The Roman Glass Company in Kibbutz Revadim, Israel.
Many museums around the world boast impressive collections of Roman glass. Yet the field remains dynamic. Rome, which produced more glass than any other previous civilization, has left footprints wherever she ruled. Since excavations are still ongoing, the serious collector can readily find authentic, high quality pieces on the market. Perfectly preserved pieces in unusual colors are the most expensive. A delicate glass flask in rare turquoise blue, for example, may command thousands of dollars. A 4th or 5th century double unguentarium, boasting blue green patina or a Late Roman hand worked miniature amphora may fetch several hundred dollars each.
Those yearning to own a bit of Roman history, but at far less expense, have several options. They can collect Roman glass beads, single or by the handful, at reasonable cost. They can purchase tiny glass figural amulets, perhaps of frogs, ducks, or fish. Adventuresome spirits can even roam the coasts from England to Libya, in search of frosted, water-smoothed Roman sea glass shards.
Shards, byproducts of the production process, were often melted down into raw glass and recycled. Broken domestic glass vessels were evidently collected for recycling too. In any case, Israeli archeologists have discovered ancient Roman glassworks surrounded by large quantities of glass chunks and fragments.
Today, modern glassworks have sprung up in their wake. Israeli artists, inspired by the past, now set blue-green glass fragments in sterling silver settings, creating necklaces, brooches, earrings, tie clips, and rings in a variety of styles. By combining ancient resources with modern technology, they bring history to life.
Melody Amsel-Arieli is the author of Between Galicia and Hungary: The Jews of Stropkov. She also writes about a broad range of antiques topics. She lives in Israel.