Copper-red glass beads of the han dynasty excavated in Yunnan Province, Southwestern China

Indo-Pacific glass beads were widespread in South, Southeast, and East Asia, as well as in Africa, and studies of these beads in China will contribute much to our understanding of early Chinese glass exploitation and maritime exchange. In this study, five tiny opaque red beads found in Muyi Cemetery, Yunnan Province, southwestern China, and dated to the Han dynasty (202 B.C.E.-220 C.E.) were analyzed to determine their production technology and to explore their possible provenance. Chemical analysis demonstrated that these beads are potash glass with higher CaO and Al₂O₃, which may have been imported from Southeast Asia, and that copper was the major coloring agent. These beads provide new evidence for early communication and trade networks between China and Southeast Asia, and for the production technology of Indo-Pacific beads. SR-pCT and SR-XRD have been shown to have a great potential in research on ancient glass beads, especially the latter, which could disclose the nature of the crystal inside the glass samples because X-rays will penetrate them during testing.