Bead Grinders and Early Swahili Household Economy: Analysis of an Assemblage from Tumbe, Pemba Island, Tanzania, 7TH-10TH Centuries AD

This paper focuses on a specific class of locally made artifacts known in the archaeological literature of the eastern African coast as bead grinders. Bead grinders are discarded potsherds or stone cobbles distinguished by long grooves abraded into their surfaces. Although they are some of the most commonly located artifacts on late first-millennium AD coastal sites, few close analyses of them have been conducted. Here we examine a particularly large assemblage of bead grinders from the site of Tumbe on Pemba Island, Tanzania, the largest such assemblage recovered from any site in eastern Africa. This essay is not aimed at determining whether or not these artifacts were in fact used to grind shell beads, the subject of considerable local debate, although we operate from that assumption. Rather, we treat them as artifacts related to production, and focus on standardization as a way to provide insight into the organization of production at Tumbe. Based on our analysis we argue that despite the intensive production implied by the sheer quantity of grinders recovered at Tumbe, the high degree of variation within relevant variables suggests that production was unstandardized and decentralized, carried on in individual households. We hope that this case study encourages more comparative research between coastal regions on bead grinders and other classes of artifacts related to production.