A set of beads made of glass, gastropod mollusk shell, and fishbone from a Swahili occupation level on Ibo Island (northern Mozambique) is dated to the eleventh and twelfth centuries AD. The chemical composition of the glass beads and their chromophores, and the shell and fishbone materials, are studied to understand the local and trading provenance of these items. Representative samples of each material, including two flat glass shards, were characterized using optical microscopy, field emission scanning electron microscopy (FESEM) with energy dispersive X-ray (EDS) microanalysis attached, UV-Vis-NIR spectrophotometry, and X-ray diffraction (XRD). Glass beads represent 60% of the bead assemblage. The shell and fishbone beads are 38.75% and 1.25%, respectively. Three groups of glasses were identified: (1) mineral-soda alumina glass beads associated with the recently identified m-Na-Al 6 group that come from Western India; (2) vegetal-soda alumina, represented by one flat glass shard probably from the Middle East, and beads of v-Na-Al glass of type A that came from Central Asia; and (3) conventional soda-lime silicate glasses, of modern chronology and probable European origin. Groups 1 and 2 show a variety of chromophores, both ionic and colloidal. A ruby-color bead was also identified as belonging to the Na₂O-ZnO-SiO₂ system and colored with cadmium sulfoselenide colloids, but this was of modern chronology. Shell beads were made from Lambis lambis gastropod mollusk shells and were locally produced. The fishbone beads may have been from a cartilaginous fish of the Chondrichthyes class, but it is difficult to specify the taxonomical level. The results of the analysis suggest that Ibo Island was integrated very early into the Swahili trade networks of the Indian Ocean.

一组由玻璃，腹足动物软体动物壳和鱼骨制成的珠子，来自伊博岛（莫桑比克北部）的斯瓦希里语占领级别，可追溯到公元11世纪和12世纪。对玻璃珠及其生色团，壳和鱼骨材料的化学成分进行了研究，以了解这些物品的本地来源和交易来源。使用光学显微镜，附有能量分散X射线（EDS）显微分析的场发射扫描电子显微镜（FESEM），UV-Vis-NIR分光光度法和X射线衍射对每种材料的代表性样品进行了表征，包括两个平板玻璃碎片（XRD）。玻璃珠占珠子组件的60％。壳珠和鱼骨珠分别为38.75％和1.25％。确定了三组眼镜：（1）来自印度西部的，与最近发现的m-Na-Al 6基团相关的矿物碳酸钠氧化铝玻璃珠；（2）植物苏打氧化铝，以一块可能来自中东的平板玻璃碎片为代表，以及来自中亚的A型v-Na-Al玻璃珠；（3）具有现代年代学和可能起源于欧洲的常规钠钙硅酸盐玻璃。第1组和第2组显示各种生色团，包括离子和胶体。红宝石色珠也被鉴定为属于Na 第1组和第2组显示各种生色团，包括离子和胶体。红宝石色珠也被鉴定为属于Na 第1组和第2组显示各种生色团，包括离子和胶体。红宝石色珠也被鉴定为属于Na₂ O-ZnO-SiO ₂体系，并带有亚硒化镉胶体，但具有现代年代学意义。贝壳珠由兰比斯腹足纲软体动物的贝壳制成，并在当地生产。鱼骨珠可能来自软骨鱼类的软骨鱼类，但是很难确定分类标准。分析结果表明，伊博岛很早就被纳入了印度洋的斯瓦希里语贸易网络。