An early Byzantine glass workshop at Argyroupolis, Crete: Insights into complex glass supply networks

Archaeometric studies on early Byzantine glass excavated in Greece are extremely scarce in the literature and almost exclusively related to small groups of samples, mainly glass tesserae. The aim of this study is to present archaeometric data of a large assemblage of early Byzantine glass excavated in ancient Lappa, modern town of Argyroupolis, SW of Rethymno in Crete. A series of salvage excavations unearthed a complex of 5 rooms, identified as a secondary glass workshop, yielding more than 1500 glass fragments of objects (mainly rims and stems of glass goblets) and glass working debris (mainly test drops, chunks etc.). The glass and the architectural remains date to the 4th to 7th c. AD. The glass is a typical soda lime silica glass, with close similarities between the chemical composition of the glass working debris and the objects found in the complex. The glass working debris can be divided in three main compositional groups, including the two well-known mineral-natmn based groups Levantine I and Foy Serie 2.1. The third compositional group of samples identified in the assemblage has a strong plant ash signature. This group, similar to one previously identified in Egypt, has been noticed here for the first time outside Egypt. There are only a few examples of Foy Serie 3.2, a composition that circulated widely in the Mediterranean during the early Byzantine period. This differentiation into four compositional groups can be also broadly linked to object types, while the glass working debris covers all compositional groups.