Southern African glass beads: chemistry, glass sources and patterns of trade

Three-hundred-and-sixty glass beads from 19 archaeological sites in southern Africa dating between about the 8th and 16th centuries AD were analyzed using LA-ICP-MS, determining 47 chemical elements. The eight different bead series, previously defined on morphological characteristics, possess different glass chemistries. Some bead series were made from plant-ash glasses, others from soda-alumina glasses. Zhizo series beads of the late 1st millennium AD were probably made from Iranian glass. Later bead series were made of glass probably manufactured in South Asia, though there are changes through time in both South Asian glass recipes and bead morphologies.