Counterfeit Glass Beads during the East African Caravan Trade: Mineralogical and Gemmological Analysis

Abstract

This article presents results from mineralogical and gemmological analyses of imperfectly made tubular beads excavated at Kilwa Kivinje, a 19th century coastal caravan terminus in southern Tanzania. These beads are unique in size, their material, and colour, in addition to lacking treated cut ends. Because of their distinctive flaw, these beads required thorough laboratory analyses to determine how they compare to other glass beads from the same archaeological context. Although 19th century European travellers’ accounts insist on glass beads being the popular commodity during the East African caravan trade, mineralogical and gemmological analyses revealed some of these beads to have been crafted from low-grade non-glass material. This prevented their standardisation in cut lengths, the permanency of coated colours, and the cut-ends treatment. These results justify speculation that these were counterfeits designed to pass for the original glass beads, possibly due to limited supply amidst high demand and the rapidly changing customer tastes for the much sought-after glass beads in East Africa during the height of the caravan trade. This is the first archaeological study in the region to examine the quality of traded glass beads during the caravan trade for their authenticity in artistry and material.