Composition and origins of decorated glass from Umayyad Cordoba (Spain)

Jorge De Juan Ares,Nadine Schibille,Maudilio Moreno Almenara,Yasmina Cáceres Gutiérrez

doi:10.1186/s40494-021-00505-4

Abstract

Recent archaeological excavations carried out in the western suburbs of Cordoba (Spain) brought to light numerous fragments of archaeological glass from the caliphal period (929–1031 CE). The typological and compositional analysis by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of 66 fragments enabled the identification of different types of base glass and glass working techniques, identifying local productions, imports and decorative imitations of eastern models. The studied fragments include Mesopotamian, Levantine, Egyptian and possibly Sicilian soda-rich plant ash glass categories, and various glass-decorating techniques such as mould-blowing, pressing, cutting, staining or gilding. The systematic comparison of the trace element patterns of several relief-cut objects identified both imported ware and a locally manufactured sample, whereas all mould-blown pieces were made from locally sourced raw materials. Iberian glassworkers seem to have preferred mould-blowing, probably because of the distinct working properties of locally available high lead glass. The results thus confirm the continuous long-distance exchange of vitreous material, as well as the existence of multiple glassmaking centres in the Iberian Peninsula, illustrating a link between secondary glass working techniques and chemical composition. Furthermore, the identification of several fragments belonging to the same object based on chemical composition allowed us to reconstruct entire vessels and thereby expand the repertoire of known typologies circulating in Umayyad Spain.

Highlights

Over the last 5 years, there has been significant progress in the study of glass compositions in the medieval Iberian Peninsula
Glass finds of the early Islamic period are relatively scarce in al-Andalus, and recycling of natron glass seems to have been the main source of supply during the first century of Islamic rule [2, 3]
Small fragments of the 66 samples were mounted in epoxy resin, polished and analysed by laser ablation inductively coupled mass spectrometry (LA-ICP-MS) at IRAMAT-CEB in Orléans following the protocols for glass analysis established in the laboratory [28]

Summary

Introduction

Over the last 5 years, there has been significant progress in the study of glass compositions in the medieval Iberian Peninsula. Umayyad glass assemblages from the late eighth and early ninth centuries identified a novel glassmaking recipe in Cordoba, using lead slag as the main ingredient [3]. This new glassmaking technology appeared independently of contemporary trends in the Islamic east, but instead bears some resemblance to high lead glass from Carolingian Europe [3]. In addition to recycling and the local production of lead glass, there is still evidence of glass imports in alAndalus in the form of early Islamic natron type Egypt 2 as well as soda-rich plant ash glass of Levantine and Mesopotamian origins These imports, pertain to finished objects rather than consignments of raw glass

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Conclusion