Glass Beads from Songo Mnara, Tanzania: Chemical Composition and Evidence for Local Bead Manufacture

TY - JOUR

T1 - Glass Beads from Songo Mnara, Tanzania

T2 - Chemical Composition and Evidence for Local Bead Manufacture

AU - Wood, Marilee

AU - Dussubieux, Laure

AU - Wynne-Jones, Stephanie

AU - Fleisher, Jeffrey

N1 - Funding Information: This research was conducted in collaboration with the Antiquities Division of the Ministry of Natural Resources and Tourism, Tanzania, under COSTECH permit number 2013-219-NA-2009-46. The Songo Mnara Urban Landscape Project was funded by the National Science Foundation (United States of America: grant BCS 1123091) and the Arts and Humanities Research Council (United Kingdom). We would also like to thank the reviewers for their valuable comments and suggestions. Publisher Copyright: © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

PY - 2022/8/5

Y1 - 2022/8/5

N2 - The fourteenth-to-sixteenth-century AD site of Songo Mnara, in the Kilwa archipelago in southern Tanzania, is a stone town with many standing coral buildings. Extensive excavations at the site have produced over 9,000 beads, 7,444 of which are glass. A subset of 140 of these was chemically analyzed using laser ablation-inductively coupled plasma-mass spectrometry, revealing a notably diverse assemblage that included four main glass types: mineral soda-high alumina (m-Na-Al), vegetable soda-high alumina (v-Na-Al), high lead glasses, and vegetable soda-lime (v-Na-Ca) glass. Here we present these types, giving the first tightly dated assemblage for the fifteenth-century coast. We then focus on two notable features of the assemblage. Among the high-lead glass beads are two types from China: one dates to the early fifteenth century and the other from about 1600. These later Chinese beads were accompanied by some of the earliest European beads (v-Na-Ca) found in eastern Africa. Their provenance and meaning are examined. Then, we discuss large folded beads that were decorated with trails of colored glass. Such beads have been recorded only at Songo Mnara and Kilwa Kisiwani, and we suggest they may have been made locally from imported v-Na-Al glass.

AB - The fourteenth-to-sixteenth-century AD site of Songo Mnara, in the Kilwa archipelago in southern Tanzania, is a stone town with many standing coral buildings. Extensive excavations at the site have produced over 9,000 beads, 7,444 of which are glass. A subset of 140 of these was chemically analyzed using laser ablation-inductively coupled plasma-mass spectrometry, revealing a notably diverse assemblage that included four main glass types: mineral soda-high alumina (m-Na-Al), vegetable soda-high alumina (v-Na-Al), high lead glasses, and vegetable soda-lime (v-Na-Ca) glass. Here we present these types, giving the first tightly dated assemblage for the fifteenth-century coast. We then focus on two notable features of the assemblage. Among the high-lead glass beads are two types from China: one dates to the early fifteenth century and the other from about 1600. These later Chinese beads were accompanied by some of the earliest European beads (v-Na-Ca) found in eastern Africa. Their provenance and meaning are examined. Then, we discuss large folded beads that were decorated with trails of colored glass. Such beads have been recorded only at Songo Mnara and Kilwa Kisiwani, and we suggest they may have been made locally from imported v-Na-Al glass.

KW - Fourteenth- through sixteenth-century AD

KW - Glass beads

KW - Indian Ocean trade

KW - LA-ICP-MS

KW - Songo Mnara

KW - Tanzania archaeology

UR - http://www.scopus.com/inward/record.url?scp=85135455749&partnerID=8YFLogxK

U2 - 10.1007/s10437-022-09484-8

DO - 10.1007/s10437-022-09484-8

M3 - Article

AN - SCOPUS:85135455749

SN - 0263-0338

JO - African Archaeological Review

JF - African Archaeological Review

ER -