New Insights into Early Islamic Glass from Jorjan by Archaeometric Investigation Using LIBS and SEM-EDXS

This study presents the analysis of nineteen glass samples from Jorjan (northeastern Iran), dating to the Early Islamic period, using Laser-Induced Breakdown Spectroscopy (LIBS) as a first approach. While LIBS allowed rapid screening of elemental patterns, its quantification is not yet fully mastered; therefore, complementary SEM–EDXS analyses were performed for comparative purposes and validation of the results. Both methods consistently show strong calcium (Ca) and potassium (K) with variable sodium (Na), indicating the dominance of plant-ash flux technology and aligning with the well-known transition from natron to plant ash in the 8th–9th centuries CE. Variability in Na (and minor Al) intensities points to multi-source raw materials and highlights Jorjan’s role in regional production and exchange along the Silk Road. We also provide an integrated spectral comparison, group the assemblage by Na and Ca peak strengths, and discuss the analytical and heritage-conservation advantages of LIBS—when supported by SEM–EDXS—for the study of archaeological glass.