  About two hundred coloured glass beads (red, yellow, green, blue, white,
black, pink, plum) were selected among the thousands of beads excavated on
Mapungubwe hill and at K2, archaeological sites in the Limpopo valley South
Africa, and have been studied with Raman scattering. The glass matrix of the
beads was classified according to its Raman signature into 3 main sub-groups
and corroded glass could also be identified. At least seven different
chromophores or pigments (lazurite, lead tin yellow type II, Ca/Pb arsenate,
chromate, calcium antimonate, Fe-S "amber" and a spinel) have been identified.
Many of the pigments were only manufactured after the 13th century that
confirms the presence of modern beads in the archaeological record. This calls
for further research to find a way to reconcile the carbon dating of the hill,
which currently gives the last occupation date on the hill as 1280 AD with the
physical evidence of the modern beads excavated on the hill.
