Strontium isotope analysis in ancient glass from South Asia using portable laser ablation sampling

In order to carry out strontium (Sr) isotope analysis, glass artefacts from South Asia were sampled with portable laser ablation (pLA), a relatively novel sampling technique that leaves damage invisible to the naked eye. Subsequently, thermal ionization mass spectrometry (TIMS) was used to obtain Sr isotope ratios after sample dissolution and separation. In this study, the goal was twofold: to determine whether the measurements of Sr isotope ratios were impacted by using a portable laser as a sample tool; and to assess the pertinence of using Sr isotope ratios to provenance Indian glass. Despite a deterioration in the precision of the measurement of the Sr isotope ratios for artefacts sampled with pLA compared with the traditional sampling method, the Sr isotope ratios of certain Indian glass are so different that this does not affect their separation but a comparison of data sets obtained using standard methods and pLA might be challenging.     

Beyond the Coastalscapes: Preindustrial Social and Political Networks in East Africa

The archaeological community worldwide now readily recognizes the role and significance of interregional interaction in the development and sustenance of urban societies (e.g., Marcus and Sabloff 2008; Sinclair et al. 2010; Trigger 2003). Over the past two decades, we have carried out a systematic, problem-oriented research program on the Kenyan coast and its hinterland in an effort to understand the ecological and cultural milieu that enabled towns and city-states to develop along the East African coast beginning in the late first millennium CE. Archaeological research complemented with historical sources of the eighteenth and nineteenth centuries shows that different scales of analysis can be used to understand the long-term history of the development of urbanism along this Swahili coast: local, regional, and trans-continental frames of reference each show that Swahili communities were part of numerous networks of interactions. An emerging picture of preindustrial urbanism shows that local, regional, and trans-continental interaction spheres tied coastal towns to the hinterland and to wider Indian Ocean commercial and social networks. Not all of the theorized links between the coastal towns and their local and regional trade and interaction partners will be visible archaeologically. We address the still poorly known elements of preindustrial regional networks of alliance and interaction spheres between urban and rural polities and argue that an integrative approach is necessary to understand the context of coastal urban society.     

High‐boron and High‐alumina Middle Byzantine (10th–12th Century ce) Glass Bracelets: A Western Anatolian Glass Industry

The trace element boron is present in most ancient glasses as an impurity, and high boron (≥ 300 ppm) marks raw material sources that are geologically specific and relatively uncommon. Recent analyses of Byzantine glass with high boron contents suggest that glass‐making was not limited to the traditional regions of the Levant and Egypt, and a production origin in or near western Anatolia is proposed. Glass bracelets from ?i?n al‐Tīnāt in southern Turkey give fresh evidence for the production and circulation of high‐boron glasses that closely correlates with object typology. The patterning of findspots suggests that high‐boron glass was closely connected to the Byzantine world.     

Teardrops at the Lake: Chemistry of New Kingdom to Makuria Glass Beads and Pendants Between the First and Second Nile Cataracts

International expeditions extensively excavated Lower Nubia (between the First and Second Nile Cataracts) before it was submerged under the waters of Lake Nasser and Lake Nubia. The expeditions concentrated on monumental architecture and cemeteries, including sites at Qustul and Serra East, where the New Kingdom, and Napatan, Meroitic, Nobadian, and Makurian-period elites and common people were buried, ca. 1400 BC–AD 1400. Although the finds abound in adornments, including bead imports from Egypt and South India/Sri Lanka, only a few traces of local glass bead-making have been recorded in Nubia so far. Based on results of laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis of 76 glass beads, pendants, and chunks from Qustul and Serra East contexts, dated between the New Kingdom and the Makuria Kingdom periods, this paper discusses the composition and provenance of two types of plant-ash soda-lime (v-Na-Ca) glass, two types of mineral soda-lime glass (m-Na-Ca), and two types of mineral-soda-high alumina (m-Na-Al) glass. It also presents the remains of a probable local glass bead-making workshop dated to the period of intensive long-distance bead trade in Northeast Africa, AD 400–600.

     

Glass Beads from 15th–17th Century CE Jar Burial Sites in Cambodia's Cardamom Mountains

A total of 74 glass beads, included as grave goods in 15th–17th century CE jar burials from Cambodia's Cardamom Mountains, were analysed using laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS). Several glass types were identified, including two subtypes of high‐alumina mineral soda glass, and lead–potash glass. The final glass type represents a newly discovered and previously unidentified type of high‐alumina soda glass, with high magnesia (m‐Na–Al Mg>). This study represents the first glass data from the mid‐second millennium CE from Cambodia and sheds light on the multiple long‐distance maritime exchange networks in which the upland people buried in the jars were participating.     

Islamic glass in the Christian Kingdom of Alwa: Chemistry of shards from Soba,Nubia, Sudan

Excavations at Soba, the capital of Alwa, between 2019 and 2022 yielded more than 30 glass fragments in addition to a glass cosmetic bottle. An analysis of 30 glass samples has identified glass belonging to a number of compositional groups. The majority of fragments were made of plant ash-soda glass produced in the Middle East (Iran, Iraq) between the 9th and 10th centuries, and in the Eastern Mediterranean (Levant and Egypt) between the mid-10th and mid-12th centuries. Seven fragments were made of mineral–soda-lime glass produced in 9th-century Egypt and three high-lead glasses find analogies in the 9th- to 11th-century glass. Archeological evidence, as well as textual sources, leave no doubt about Alwa’s intense transcultural connections. This article provides the first insight into the chemistry of glass shards from medieval Nubia, and the results of analysis contribute to evidence for long-distance contacts of Soba, the capital of one of the medieval kingdoms of Sahelian Africa.     

The first direct evidence of pre-columbian sources of palygorskite for Maya Blue

Maya Blue, a nano-structured clay–organic complex of palygorskite and indigo, was used predominantly before the Spanish Conquest. It has fascinated chemists, material scientists, archaeologists and art historians for decades because it is resistant to the effect of acids, alkalis, and other reagents, and its rich color has persisted for centuries in the harsh tropical climate of southern Mesoamerica. One of its components, palygorskite, is part of modern Maya indigenous knowledge, and ethnohistoric and archaeological data suggest that its modern sources were probably utilized in Prehispanic times. Yet no direct evidence verifies that palygorskite was actually mined from these sources to make Maya Blue. Here we characterize these sources compositionally, and compare our analyses to those of Maya Blue from Chichén Itzá and Palenque. We demonstrate that the palygorskite in most of these samples came from modern mines, providing the first direct evidence for the use of these sources for making Maya Blue. These findings reveal that modern Maya indigenous knowledge about palygorskite, its mining, and its source locations, is at least seven centuries old.     

Mineral soda alumina glass: occurence and meaning

Mineral soda–alumina (m-Na–Al) glass has been found across a vast area stretching from Africa to East Asia. m-Na–Al glass appears around the 5th c. B.C. and is relatively common for periods as late as the 19th c. A.D. It is particularly abundant in South Asia, where raw materials to produce m-Na–Al glass are readily available, and was likely manufactured there; however, the number and the importance of the manufacturing centers is unknown as archaeological information are extremely scarce. The interpretation of data obtained using compositional analysis on a large corpus of artifacts (486) shows that at least five sub-groups of m-Na–Al glass can be identified using the concentrations of calcium, magnesium, uranium, barium, strontium, zirconium and cesium measured with laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS). From this data, it is possible to infer the existence of several m-Na-Al glass making centers, not all of them located in South Asia as previously assumed. They were operating over different time periods and were connected to different exchange networks.     

Beads from a mediaeval pilgrim centre: Chemical composition and provenance of glass from Banganarti,Nubia, Sudan

Christian Nubia was a region with intensive transcultural connections that are visible through the understudied overseas glass bead imports found there. This paper presents the results of an analysis of 20 glass beads from Banganarti, a Christian pilgrim site active during the Makuria kingdom (mid-sixth to 14th centuries CE). Compositional analyses using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) have identified glass belonging to a number of broad compositional groups. Two beads were made of mineral soda-lime glass, dated before the mid-ninth century CE. Numerous beads were made from plant ash-soda-lime glass associated with “Mesopotamian” production dated between the eighth and 10th centuries CE. Lead-soda-silica glass has parallels in the ninth–10th centuries glass found in Africa and Europe. One plant ash-soda-lime bead was of eastern Mediterranean origin dated after the 10th century CE. Results of this study provide new evidence for provenance and chronology of glass beads available in the mediaeval Northeast Africa as well as contribute new data to the research on the pilgrim and/or trade routes of that time.     

Overseas imports on the Blue Nile: Chemical compositional analysis of glass beads from Soba,Nubia

Archaeological evidence as well as textual sources leave no doubt about Alwa's (Alodia's) intense transcultural connections, further corroborated by understudied overseas glass bead imports found there. This paper presents results of an analysis of 23 glass beads from Soba, the most prosperous capital of medieval Nubia. Compositional analyses using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) have identified glass belonging to a number of broad compositional groups. Three samples were made of soda lime low-alumina glass produced in the Middle East (v-Na-Ca) and Egypt (m/v-Na-Ca). The remaining beads were made of two types of mineral–soda high-alumina glass (m-Na-Al) North Indian in origin. The results of this study provide new evidence for the provenance and chronology of glass beads available in medieval Soba and Northeast Africa, and contribute new data to research on trade contacts of that time.