Abstract
This paper analyzed three glass beads unearthed from M686 in the Qin Cemetery of Warring States Period (475 BC-207 BC) in Hejia,Zhouling by using ultra depth of field 3D video microscopy (OM), X-ray fluorescence spectroscopy (XRF) and microscopic laser Raman spectroscopy. The results show that the three glass beads belong to the unique lead-barium silicate glass system in ancient China. The main chromic element of glass is Cu(Ⅱ), and the weathering products are PbCO3 and BaSO4. And taking the cross section of sample 2 as the main research object, the weathering mechanism of lead-barium glass was studied by means of scanning electron microscope energy spectrum scanning (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). The weathering of lead-barium glass was caused by the continuous loss of Pb, Ba and S elements in the substrate, and the interaction with the materials in the buried environment to produce the weathering products of PbCO3 and BaSO4. Based on the analysis of soil elements in the buried environment, the water solubility of Ba ion is greater than that of Pb ion. The weathering process of glass is accompanied by the transformation of Cu(Ⅱ) to Cu(Ⅰ), which explains the essence of weathering discoloration of glass. This study has reference significance for the research of production process, weathering mechanism and protection of lead-barium silicate system.