Final Report Summary - ARCHGLASS (Archaeometry and Archaeology of Ancient Glass Production as a Source for Ancient Technology and Trade of Raw Materials)
In the ARCHGLASS project, new techniques to reconstruct ancient economies are developed. These are applied to the Hellenistic-Roman glass trade. Innovative isotope geochemical methods to analyse glass and its raw materials are developed and refined, using the elements strontium, neodymium, boron and antimony. A practical database of suitable sands for glass making, sampled from around the entire Mediterranean, is made. Such information allows the primary provenance determination of natron glass from the Hellenistic-Roman world. From archaeological and archaeometrical analyses, it is clear that suitable sands for natron glass making are rare. Glass factories in the eastern Mediterranean and possibly Italy were active from the onset of natron glass making. Likely other producers in the western Mediterranean or north Africa were also active from the 5th century BC onwards, but in a much more limited way. From imperial – early Roman times onwards, throughout the 1st century AD to the first half of the 5th century AD, the origin of primary natron glass lies in the western as well as in the eastern Mediterranean and Italy. Apparently, investments were made in several glass making units all over the Empire. It is tempting to link this development in the glass industry to the end of the Roman Republic and the beginning of the Roman Empire, when Augustus introduced a series of reforms leading to a period of flourishing trade between Rome and her many and varied provinces, next to the impetus of the invention of glass blowing, making glass a ubiquitous utilitarian material. Most glass has a signature typical for a Syro-Palestinian or (possibly) an Italian provenance. Clear western Mediterranean or north African signatures are a minor part of the dataset. The western Mediterranean or north African and the presumed Italian production of glass slowly dies out towards the end of the 5th century AD. It is tempting to relate this process to the fall of the western Roman empire. By the 3rd century AD, the picture of peaceful commerce throughout the Roman world changes. Devaluation of coinage and an increase of inflation led to goods only being produced and sold locally; mass production for export was no longer possible. By the end of the 3rd to the start of the 4th century AD, the empire is split into East and West. As the market and transport mechanisms for glass factories around the empire would have been dissolved, in late Roman to early Byzantine/Islamic times, from the 5th century AD onwards, natron glass making falls back exclusively on the glass producing sites in the eastern Mediterranean, both in Syro-Palestine and Egypt. In terms of the flux source, all ancient natron glass analysed here is very homogenous in composition, and very similar to natron sources from north Africa. The recent discovery of natron deposits outside Egypt moreover shows that there may be many such sources yet undiscovered in this part of the Roman world. The occurrence and mining of natron throughout north Africa would make the supply of this raw material across the Mediterranean to primary factories in Italy of the western provinces much easier, even with overland transport. With the results obtained so far, the Wadi Natrun as a (one of the) main source of natron for the Roman world remains likely. The discovery of this new phasing in glass making in the Hellenistic-Roman world adds a new chapter to the history of glass and our knowledge of the archaeological record, now to be integrated in further economic studies of the Roman world.