Exotic treasures or local innovation: Gold and silver beads of han dynasty excavated from Nanyang City, Henan Province, central China

Abstract

The emergence and utilization of gold beads in China were influenced by foreign civilizations and cultures, while the exploration of composite beads in China has been relatively limited compared to single-material beads. Metal foil glass beads represent a distinct type of composite beadwork popular in ancient times. This paper presents findings from a study conducted on a group of beads that were unearthed in Nanyang City, Henan Province. Theoretical calculations and CT imaging suggested that a particular class of gold beads, previously misidentified as single-material beads, actually consisted of gold foil wrapped around an inner layer of glass beads. Elemental analysis techniques such as pXRF, SEM and μ-EDXRF were used to reveal that the purity of the gold foil of the two differently shaped beads is around 95% and 98.5%, while the silver foil of the silver beads is also around 85% due to corrosion. Microscopic observation confirmed that the gold leaf was applied through foil-fusion gilding. Lead isotope analysis indicated that the gold beads originated from different sources, whereas the silver beads likely originated from the Central Plains region. Furthermore, the evidence of beadwork from Southeast Asia and South China supports the view that the gold beads may have been originally exotic but gradually adaptated through indigenous learning, allowing the creation of high-quality imitations. This study emphasizes the importance of scientific analyses for the proper determination of bead types and craftsmanship, and contributes to a better understanding of the ancient bead circulation network.