Glass Wires from Chogha Zanbil: Preliminary Glass Making Evidence in Iran in the Early 2rd Millennium BC

Abstract

Glass is one of the oldest materials which have been used in human history. Till nowadays, glass has not lost its attraction. The macroscopically character of this object make it usable for many different applications. Whether its transparency or its opacity, this object is the most fascinating material. Indeed, the history of glass making goes back to the 3th Millennium BC in Near East and Levant, but the early supported documentation with regard to the fabrication of this material goes back to the 2th Millennium BC. The glass wires from Chogha Zanbil are the unique and most considerable objects from Elamite period (2th Millennium BC). Chogha Zanbil glass wires are also known as the first evidence for glass-making in the second millennium BC in Iran and are of particular importance due to their material characteristics, manufacturing technique, their form and style. In this research, two pieces of glass wares belonging to the 2nd millennium BC from Chogha Zanbil, in the Abadan Museum, were subjected to chemical and structural investigations. The main question discussed in this paper is to determine the chemical composition as well as crystalline phase constituents of these materials, technological features and determining the firing temperature of these glass objects. QPXRD method was used to identify the crystalline structure of these materials. The microstructure and texture of the objects were studied and analyzed using ESEM-EDX method. Firing temperature of these wires was investigated by means of simultaneous thermal analysis (STA) method in order to estimate the manufacturing temperature. Mineralogical chemical studies indicate that these objects are in fact high-temperature ceramics, which have a glassy fabric. It occurs when the heating temperature passed the transition state. Glass transition relates to the transition from the solid state to the liquid state (or the reverse one). It is basically a kinetical phenomenon. It denotes to the so-called "structural relaxation". If the structural relaxation has time enough to happen during the statement time, the material behaves as a liquid. If the structural relaxation cannot occur during experience time, then the material behaves as a rigid -or semi rigid- solid. The external and internal layer of glasses seems to be a crystalline part with the effect of both sintering and partial smelting. The manufacturing temperature of these materials has reached about 1000-1100 ºC, and it has led to the glazing effects of glass on their surface.