Glass Networks: Tracing Early Medieval Long-Distance Trade, c. 800-1000 (IMC Leeds 2020 Session 819) (original) (raw)
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Open Access Journal of Archaeology and Anthropology, 2023
The current project focuses on the chemical analysis of utilitarian glass objects of the post-Byzantine period, from two sites in mainland Messenia, Peloponnese, southern Greece: Androusa and Alagonia. The assemblage consists of 48 glass fragments of vessels, drinking vessels and glass panes. The vast majority of the samples are colourless or naturally coloured, although there are also a few blue, green and amber samples; few samples present decoration, primarily with engraved and enamel patterns. Their exact date is uncertain; they are placed between the 15 th and 19 th c. Based on the chemical and mineralogical analysis (carried out via SEM/EDS, p-XRF and Raman) a complex image emerges, suggesting the use of varied raw materials (Na-or K-rich plant ash, potash, saltpetre as the alkali source; manganese and arsenic as decolourants; tin oxide and calcite as opacifiers). Given that during this period there was a high diversity in the manufacturing technologies used in glass workshops from different areas, it is possible to identify glasses originating from both the eastern regions of the Ottoman Empire (following the Islamic tradition of glass making) and from Europe (e.g., Bohemian glass). Comparing the glasses of these two sites with previously studied assemblages from Messenia provided with valuable new information regarding the production and trade of glass in mainland Greece during the post-Byzantine period. Overall, a complex trading network is suggested, both for low-quality utilitarian objects and for higher quality luxurious glasses, which is even more intriguing given that neither of these sites had a port and, therefore, direct access to the significant marine trading networks of the period.
Chemical Papers
The history of the production of glass objects started about 3500 years ago. Glass is a fascinating material with a cultural and technological history: the integrated approach of scientific and traditional archaeological issues contributes to the reconstruction of the production technology of artefacts, as well as their trade and exchange. The findings from excavations in the territory of Ravenna (Italy) are the starting point for the reconstruction of the possible contacts between Italy and Central Europe. In Medieval times, glass vessels of different types, firstly produced in Mediterranean regions, spread to many areas. The present work analyses the possible typological and chemical affinities between a set of samples, dated back to the 13th - 16th centuries, found in the archaeological excavations of the Monastery of Saint Severus (Classe, Ravenna) with the same type of glasses found in different regions of Central Europe. This work reports and discusses data obtained by archaeological and archaeometric studies of three glass vessel types: prunted beakers, so-called kropfflasche and ampoules. The prunted beaker (nuppenbecher, verre a gouttes) - cylindrical vessels decorated with protrusions along the body - was probably made by Italian glassblowers in 13th-15th century; it reached Central Europe and appeared in numerous archaeological site from France to Czech Republic (Han 1975; Newby 1985; Whitehouse 1985; Gyürky 1986; Newby 1991; Foy e Bailly-Maître 2014; Sedláčková et al. 2014). “Kropfflasche” is a particular type of globular bottle, produced in the 13th-14th century. Similar bottles were be found in: Herzegovina (Andjelić 1975; Wenzel 1975), the Duke’s Palace of Budapest (Gyürky 1986), Czech Republic (Sedláčkovà 2006), Bohemia (Hejdová e Nechvátal 1970) and France (Harden 1971). The last type of the analysed glass – the ampoule - became very common from the end of the 13th century in ecclesiastic sites, used for consecrate oil or wine. Archaeological contextualisation of the site and chrono-typological study of glass vessels were associated to chemical analyses, performed to characterise the composition of the glassy matrix (major and minor components as well as trace elements). The results were elaborated according to the archaeometric glass classification and provenancing of raw materials, shedding new light on glass production in late Medieval times and interpreting the relations and the exchanges between geographical areas and related cultures.
Changes in the supply of eastern Mediterranean glasses to Visigothic Spain
Journal of Archaeological Science, 2019
This study presents the first comprehensive analysis of glass compositions from Visigothic Spain using high resolution laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). Major, minor and trace element patterns of 169 well-dated samples from three rural Iberian sites (Congosto, Gózquez and El Pelícano) have brought to light major chronological developments in the production, circulation and use of glass between the fifth and the eighth century CE. The data identify four distinct compositional groups of Egyptian and Levantine origin. Egyptian Foy 2.1, Foy 2.1 high Fe and so-called Magby alongside Apollonia-type Levantine I were the main glass types of the Visigothic period. Due to the tight dating of the majority of the samples, we were able to reveal fundamental changes in the geographical scope of glass supplies to the Iberian Peninsula, and to refine the chronological range of the known primary production groups. The glass group commonly known as série 2.1 or Foy 2.1 started being produced already during the second half of the fifth century. The appearance of Foy 2.1 high Fe can likewise be moved forward to the first half of the sixth century. A plant-ash group referred to as Magby was introduced around the middle of the sixth century. Egypt was undeniably the main supplier of raw glasses to the Iberian Peninsula up to the mid-sixth century CE, after which the Levantine I group became the prime glass type among the analysed assemblages. In the final stages of the Visigothic Kingdom and the early years of Islamic dominion, there is a noticeable drop in the absolute quantity of glass available, together with an increase in recycling. The implications of these transformations in the supply of glass for the organisation of Mediterranean trade are discussed.
BEADS: Journal of the Society of Bead Researchers, 2021
The Venetian glass bead industry has its roots in the Late Middle Ages. The development of Atlantic trade and, particularly, the slave trade from the second half of the 17th century increased the demand for glass beads. The 18th century would be the heyday of this industry, when Venetian beads attained a significant global diffusion. While scholars have long known the global exports of beads from Venice, this paper contributes new quantitative data on their precise routes and markets in the 18th century, toward the Orient and toward the Atlantic. Using beads as a case study, this paper shows how a niche product allowed a Mediterranean city such as Venice to stay connected with the Atlantic world and how the Atlantic slave trade influenced Venetian glass bead exports to the West.
Archaeology. Just Add Water. Underwater Research at the University of Warsaw, 2018
The following article is the development of the selected glass finds from the Begastri site in the south- -eastern part of the Iberian Peninsula (Region of Murcia). Being conducted there since the 1980s, excavations on behalf of the University of Murcia have brought to light numerous glass objects. The chronological and typological elaboration of these objects is difficult due to the very poor state of preservation; therefore, in relation to these finds, a decision was made to finance the physical and chemical research. By determining the chemical composition of individual samples, one can deliberate upon the provenance of the raw glass from which the objects were made. Determining the place of origin of glass ingots allows also designating presumed trade routes and means used to transport them.
One hundred and forty-one glass fragments from medieval Ciudad de Vascos (Toledo, Spain) were analysed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The glasses fall into three types according to the fluxing agents used: mineral natron, soda-rich plant ash, and a combination of soda ash and lead. The natron glasses can be assigned to various established primary production groups of eastern Mediterranean provenance. Different types of plant ash glasses indicate differences in the silica source as well as the plant ash component, reflecting changing supply mechanisms. While the earlier plant ash groups can be related to Islamic glasses from the Near East, both in terms of typol-ogy and composition, the chemical signature of the later samples appear to be specific to glass from the Iberian Peninsula. This has important implications for our understanding of the emerging glass industry in Spain and the distribution patterns of glass groups and raw materials. The plant ash that was used for the Vascos glasses is rich in soda with low levels of potash, similar to ash produced in the eastern Mediterranean. It could therefore be possible that Levantine plant ash was imported and used in Islamic period glass workshops in Spain. Unlike central and northern Europe where an independent glass industry based on potassium-rich wood ash developed during the Carolingian period, the prevalence of soda ash and soda ash lead glass on the Iberian Peninsula indicates its commercial and technological interconnection with the Islamic east. Our study thus traces several stages leading to the development of a specifically Spanish primary glassmaking industry.