Strontium Isotopes in the Investigation of Early Glass Production: Byzantine and Early Islamic Glass from the Near East*

Abstract

87Sr/ 86 Sr ratios have been determined for glasses from four production sites, dated to between the sixth and the 11th centuries, in the Eastern Mediterranean region. On the basis of elemental analyses, the glasses at each location are believed to have been melted from different raw materials. Two glass groups, from Bet Eli'ezer and Bet She'an, in Israel, are believed to have been based upon mixtures of Levantine coastal sands and natron, and have 87 Sr/ 86 Sr ratios close to 0.7090, plus high elemental strontium, confirming a high concentration of modern marine shell ( 87 Sr/ 86 Sr ~ 0.7092) in the raw materials. The isotopic compositions of these two groups of glasses differ slightly, however, probably reflecting a varying ratio of limestone to shell because the sands that were utilized were from different coastal locations. Natron-based glasses from a workshop at Tel el Ashmunein, Middle Egypt, have 87 Sr/ 86 Sr values of 0.70794-0.70798, and low elemental strontium, consistent with the use of limestone or limestone-rich sand in the batch. High-magnesia glasses based on plant ash, from Banias, Israel, have 87 Sr/ 86 , probably reflecting the isotopic composition of the soils that were parental to the plants that were ashed to make the glass. Strontium and its isotopes offer an approach to identifying both the raw materials and the origins of ancient glasses, and are a potentially powerful tool in their interpretation.

Chemical characterisation of archaeological glasses from the Hellenistic site of Jebel Khalid, Syria by electron probe microanalysis

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Archaeological and archaeometric study of the glass finds from the ancient harbour of Classe (Ravenna- Italy): new evidence

“…Recent studies have demonstrated the great potential of isotopic analysis for glass provenance study in the case of Roman, Late Antique and Byzantine glass [22,[37][38][39][40].…”

Glass Making in the Greco-Roman World: Results of the ARCHGLASS project

“…Therefore, something more than just the bulk chemical data of the glasses is needed to enable successful provenancing. Several attempts have been made to use a variety of techniques to provenance glass, these include trace element analysis, rare earth element patterns and isotopic signatures Degryse and Shortland, 2009;Freestone et al, 2003;Henderson et al, 2005;Shortland et al, 2007;Wedepohl and Baumann, 2000). In particular, Sr-Nd isotopic signatures have been used to indicate that the majority of the Roman glass found in Europe came from the Eastern Mediterranean region (Freestone et al, n.d.).…”