Analytical Studies and Identification of Production Process in the Glass Objects from the Underground Hand-Made Architectural Complex of Arzanfood, Hamedan

Study on the production technology in ancient glass artefacts is one of the interesting subject in the field of archaeological sciences. The aim of this study is to identify the chemical composition and production technology in the glass objects discovered form the underground hand-made architectural complex of Arzanfood, near Hamedan, in western Iran. These objects are including some broken pieces of glass vessels, glass bracelets and one piece of a glassy material without specific shape. To characterize the technology of glass production in the glass objects from Arzanfood, 12 samples from broken vessels, bracelets and the glass piece without specific shape were analyzed by analytical instruments. Based on the archaeological studies in the site, these objects are dated to Sasanian and middle Islamic periods. For chemical analysis, the samples were analyzed by inductively coupled plasma- mass spectroscopy (ICP-MS) method to measure major, minor and trace constituents, and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) to observe the microstructural features. The results show that soda-lime glass (soda-lime-silica glass with plant ash) has been used to make the glass objects. Only in the no-shape piece a completely different composition is visible including different content of major and minor constituents in comparison with other glass objects. The microstructure of samples represents two different types of glass matrix including homogenous glass matrix and glass matrix with significant amounts of high-lead and high-tin phases. Presence of lead and tin phases in the microstructure of these objects is due to use lead and tin compounds as opacifier in the composition of glass material used in manufacturing the objects.