Ancient Glass Bead from U-Thong Ancient City Site, Central Thailand

Abstract

The goal of this research is to build a database for the ancient glass beads from U-Thong excavation site (Dvaravati Period, 6th to 13th centuries). We can compare the chemical properties among the ancient glass beads from different sites in order to learn about the ancient trading route of those glass beads. The 30 samples and 12 colors (translucent to opaque and various colors) were collected from U-Thong archaeological site, Suphanburi Province, Central Thailand. The ancient glass bead samples were studied about the physical and chemical characteristics as well as the surface features. The glass beads were analyzed by the scanning electron microscope coupled with energy dispersive x-ray spectrometer (SEM-EDS), Fourier transform infrared spectrometer (FTIR) and Atomic Force Microscope (AFM). The chemical composition of the dark blue bead for example contained 2.25 wt% MgO, 90.98 wt% SiO2, 1.26 wt% K2O, 4.17 wt% CaO and 0.59 wt% CuO. The FTIR spectrum of ancient glass beads is rarely to interpret their molecular vibration. The AFM allowed us to see the glass corrosion in nano scale on the surface. This research can help Thai archaeologists to identify the characteristics of ancient glass bead in the Central Thailand.