Elemental and Sr/Nd isotopic investigation of late Hellenistic to early Roman glass bowls
Channel: Recording Archaeology
Date: 2017-01-07

Excavations in the Souks area of Beirut, Lebanon, not only revealed large amounts of glass artefacts from the Hellenistic to the Islamic period1 but also remnants of primary tank furnaces, dating to the early 1st century CE2. We determined the major elemental compositions of 66 mid-2nd century BCE – early 2nd century CE cast glass bowls from Beirut via electron microprobe. 41 beach sand samples taken along the coastline of Lebanon were analysed for their major elemental compositions via ICP-OES. A selection of sand and glass samples were subjected to Sr and Nd isotopic analysis. Results were compared to the composition of glass from the tank furnaces3 and Lebanese sandsto investigate the possibility of a localorigin. All glasses were soda-lime-silica in composition, with natron as a flux. Strongly coloured glass was coloured with Co, Cu and Mn. Pale coloured glass has varying MnO, up to 1.9%, suggesting that they were intended to be colourless. Colourless bowls can be divided into three groups: Mn-, Sb- and mixed Mn-Sb-decoloured glass. All Mn-decoloured, pale and strongly coloured vessels have closely similar base glass compositions to glass from the tank furnaces3, suggesting local production and working. The Sb-decoloured glass was made from a different sand source with higher Si2O and lower Al2O3 and CaO. Mixed Mn-Sbdecoloured glass has intermediate compositions, suggesting they are theresult of recycling. Sr and Nd isotopic analyses confirm the different primary origin of the Sb-decoloured glass. The isotopic signatures of the other glasses correspond well to those measured in some of the Lebanese sands, suggesting they were indeed produced locally.
1 S. Jennings, Vessel glass from Beirut (Bey 006, 007 and 045), Berytus Archaeological Studies 48-49, 2006.
2 I. Kouwatli, H.H. Curvers, B. Stuart, Y. Sablerolles, J. Henderson, P. Reynolds, A pottery and glass production site in Beirut (BEY 015), Bulletin
d’Archéologie et d’Architecture Libanaises 10, 103-130, 2008.
3 J. Henderson, Ancient glass: An interdisciplinary exploration, Cambridge University Press, pp. 423, 2013.

Author - Brems, Dieter, KU Leuven, Leuven, Belgium (Presenting author)
Co-author(s) - Freestone, Ian, University College London, London, United Kingdom
Co-author(s) - Griffiths, Dafydd, University College London, London, United Kingdom
Co-author(s) - Degryse, Patrick, KU Leuven, Leuven, Belgium
Keywords: Natron glass, Sand raw materials, Isotopes