Capital of the Abbasid Caliphate between 836 and 892 CE, the palace-city of Samarra offers a precise window into early Islamic art and architecture. Excavations conducted more than 100 years ago are seen as the beginnings of scientific Islamic archaeology, and have yielded an exceptional array of finds including a wealth of glass artefacts. The chemical composition of glass reflects the nature of the raw materials and their geological provenance and can therefore reveal past technologies and economic and cultural interactions. Through high-resolution analysis of a comprehensive glass assemblage from Samarra we have new evidence that points to the existence of an advanced Abbasid glass industry, as well as the import of specific glass objects for the thriving new capital city. Quantitative analytical data of 58 elements by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) show a striking correlation between object types and glass compositions. The compositional profiles of two related plant ash groups of architectural glass point to a local production, destined for the decoration of the famed glass walls of Abbasid palaces. The selective use of objects, materials and colours to create reflective and luminous glass walls are indicative of the great cultural and economic value of glass during the Abbasid period. Our findings thus confirm the veracity of written sources that stipulate the production of glass in the vicinity of Samarra, as well as the import of selected artefacts such as Byzantine mosaic tesserae.

The understanding of the glass trade in the first millennium CE relies on the characterisation of well-dated compositional groups and the identification of their primary production sites. 275 Byzantine glass weights from the British Museum and the Bibliothèque nationale de France dating to the sixth and seventh century were analysed by LA-ICP-MS. Multivariate statistical and graphical data analysis discriminated between six main primary glass types. Primary glass sources were differentiated based on multi-dimensional comparison of silica-derived elements (MgO, Al₂O₃, CaO, TiO₂, Fe₂O₃, ZrO₂) and components associated with the alkali source (Li₂O, B₂O₃). Along with Egyptian and Levantine origins of the glassmaking sands, variations in the natron source possibly point to the exploitation of two different natron deposits. Differences in strontium to calcium ratios revealed variations in the carbonate fractions in the sand. At least two cobalt sources were employed as colouring agents, one of which shows strong correlations with nickel, indicating a specific post-Roman cobalt source. Typological evidence identified chronological developments in the use of the different glass groups. Throughout the sixth century, Byzantine glass weights were predominately produced from two glasses that are probably of an Egyptian origin (Foy-2 and Foy-2 high Fe). Towards the second half of the sixth century a new but related plant-ash glass type emerged (Magby). Levantine I was likewise found among the late sixth- to early seventh-century samples. The use of different dies for the same batch testifies to large-scale, centralised production of the weights, while the same die used for different primary production groups demonstrates the co-existence of alternative sources of supply. Given the comprehensive design of our study, these results can be extrapolated to the wider early Byzantine glass industry and its changes at large.

Glass is one of several early modern industries where the development from small-scale workshop to large-scale industry offers a valuable insight into wider socio-economic trends. Previously, medieval and early modern forest (wood ash) glass has been studied using a range of analytical techniques. However, characterisations of production centres and exchange systems for forest glasses are difficult to verify, in part because very few examples of raw glass from furnace sites have been investigated. Compositional analysis can provide evidence for the raw materials used and can sometimes provide compositional groupings specific to sites. However, strontium and neodymium isotope determinations can actually provenance the glass by linking the geological ages, or sources, of raw materials to production sites. Using EPMA fifty-six raw glass samples from four sites in two English production areas in operation during the 14^th and 16^th centuries have been analysed. These analyses have shown that the main products of these sites were potash-rich, wood or bracken ash glasses. However, the chemical composition does not provide sufficient resolution to identify differences between the two English regions or the sites within these regions. A subset of five raw glass samples from each of these sites have also been analysed using TIMS to determine strontium and neodymium concentration and isotope ratios. The results allow glasses produced in each region to be differentiated, and can even be used to divide glass production sites within the regions.

This article presents the curatorial context of a newly discovered fragment of Minoan faience, now in the Bristol City Museum and Art Gallery (BCMAG), and the technological study conducted on this piece at the British Museum. It also discusses the British Museum study of comparable fragments, now in the Ashmolean Museum, belonging to the Town Mosaic from Knossos, an important and unique find brought to light during Sir Arthur Evans's excavations of the ‘Palace of Minos’ at the beginning of the twentieth century. Both the stylistic study and the analytical results suggest that the Bristol fragment is genuine, and most likely belonged to the Town Mosaic. The Bristol piece does not possess features that can advance our understanding of Crete in the Bronze Age, but its curious biography adds something to the history of collecting and the history of archaeology.