Scientific and technical analysis of lead-barium glaze dragonfly eye beads from the Late Warring States period in China

Abstract

This paper analyzed five dragonfly eye beads excavated from M176 of the Hejia Cemetery in the Late Warring States period (around 3rd c. BC) by using a super depth of field 3D microscope system (OM), scanning electron microscope-energy dispersive spectrum (SEM–EDS) and Raman spectroscopy. The analytical results confirmed that all the beads were glazed pottery and the glaze material belongs to the lead-barium-silicate (PbO-BaO-SiO2) system. The color component of the glaze is Chinese Blue (BaCuSi4O10). Three beads, M176-2, M176-3, and M176-4, were formed with an inner core support and were made in the same batch. Additionally, two weathering products, CuPb4(SO4)2(OH)6 and PbCO3, were detected on the glaze layer surface. The results of scientific and technological analysis show that these beads have differences in the composition of the body and glaze, and the color composition in the glaze layer is relatively rare in previous studies. The discovery of lead-barium glazed pottery beads from the Late Warring States period in northern China provides new evidence for further exploration into the origins and evolution of early glazed pottery. The identification of weathering products formed on the beads’ surface within an alkaline burial environment holds valuable implications for the study of weathering and deterioration in silicate artifacts.