Pliny the Elder's "Natural History" is often cited in studies of ancient natron glass production. Pliny describes the production of glass using sand from the Belus River in Israel and the Volturno River in Italy. He also mentions that glass was similarly made in France and Spain, however, with no direct archaeological evidences has ever been found to support glass production in these regions. In this study the authors investigate the possible existence of a Roman primary glass industry in the western Mediterranean, based on the occurrence of natron glass. The results show that good glass making sands are far from common. Only six limited areas could be defined where suitable sand raw materials would have been available to the Roman glassmaker. The rest of the sands are unsuitable for glass production in their present form. The suitability of the suggested sands was checked by performing a series of melting experiments, which provide further insights in the way Roman glass makers would have had to prepare their raw materials and the used batch recipes.
