Chemical and lead isotope analysis of some lead-barium glass wares from the Warring States Period, unearthed from Chu tombs in Changde City, Hunan Province, China

In the context of the present study, we have conducted chemical and lead isotope analyses on twelve ancient glass samples unearthed from Chu tombs in Changde City, Hunan Province. The results of the chemical analysis of these samples show that all samples are PbO―BaO―SiO2 glasses, thus indicating that they are all traditional ancient Chinese glasses. The chemical results also suggest that all Bi wares may either share a common source or were produced according to similar recipes. In turn, the eye beads are different from the Bi wares for their distinct chemical composition. The chemical results indicate that silica, lead-bearing material, barium-bearing material, and sodium/lime-bearing material are the main independent components of the raw materials employed in the production of these glass wares. However, the lead isotope data pertaining to the Changde lead-barium glass wares show a wide variety of lead isotope ratios corresponding to lead-barium glasses, ranging from the highest to the lowest groups of ancient lead-barium glasses identified in the existing literature. Furthermore, the lead isotope analysis (LIA) results are not consistent with the results of the chemical analysis, for the latter suggest that the different chemical compositions of the Bi wares and the eye beads were not caused by distinct ore sources, but by different technologies. The LIA results also indicate that the early Chinese lead-barium glasses with the lowest and highest 207Pb/206Pb values were mainly made in the southern region of the ancient Chu Kingdom during the Warring States Period.