Journal of Archaeological Science: Reports 51 (2023) 104145 Available online 10 August 2023 2352-409X/© 2023 Elsevier Ltd. All rights reserved. Fragments of luxury: Opaque glass from the Palace of Mystras, Greece Eleni Palamara a, b, * , Dimitrios Palles c , Efstratios I. Kamitsos c , Partha Pratim Das d , Juan I. Tirado e , Stavros Nicolopoulos f , Nikolaos Zacharias a a Laboratory of Archaeometry, University of the Peloponnese, Old Camp, 24133 Kalamata, Greece b Art-E Solutions PC, 18 Sfaktirias Str, 24133 Kalamata, Greece c Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 11635 Athens, Greece d Electron Crystallography Solutions SL, Calle Orense 8, 28020 Madrid, Spain e Instituto de Tecnología Química (UPV-CSIC), Universitat Polit` ecnica de Val` encia-Consejo Superior de Investigaciones Científcas, Avenida de los Naranjos s/n, 46022, Valencia, Spain f NanoMEGAS SPRL, Rue ` Emile Claus 49 bte 9, 1050, Brussels, Belgium A R T I C L E INFO Keywords: Post-Byzantine glass Mystras Opaque glass Ca-phosphate Red glass ABSTRACT The present study focuses on the analysis of nine opaque or translucent glass samples of white, grey/blue and red colour, recovered from the Palace Complex of Mystras in southern Peloponnese, Greece. Their date cannot be determined with specifcity but has to span between the mid-13th and mid-19th c. AD, the period since the construction of the site and throughout its continuous use as the administrative centre of the Despotate of Mystras. The extremely rare occurrence of opaque glass vessels of this period in Greece, as well as the recovery of most samples within Building E of the Complex, suggest that the samples were precious objects, possibly owned by high ranking members of the Palace. A multi-technique approach, including Optical microscopy, SEM/EDS, Raman spectroscopy and TEM analysis, was implemented in order to determine the microstructure and raw materials of the samples. Despite the small number of samples, a remarkable variability was revealed in terms of the raw materials and manufacturing processes employed. Overall, three different opacifcation techniques were documented among the white and grey/blue samples: The Na-rich glasses were opacifed using either cassiterite, a typical opacifer for the period, or calcium antimonate, a less common opacifer in the post-Medieval glassmaking. The K-rich white glasses were opacifed with the addition of the ashes of animal bones, as suggested by the presence of calcium phosphates, a Byzantine tradition that was possibly also used by Bohemian glassmakers. Finally, the red glasses present certain atypical traits in their microstructure and chemical composition. The samples contain multiple calcite, tin oxide and lead oxide particles. The colour is due to copper, which could only be identifed with the application of TEM analysis, in the form of copper oxide nanoparticles. The present study highlights the complicated traditions employed for the production of opaque glass in the post-Medieval European workshops and it underscores the need for a more thorough study of related material. 1. Introduction Opaque coloured glass has been extensively used for millennia to imitate semi-precious or precious stones and to create luxurious glass artefacts. During the Medieval and post-Medieval period, the written sources reveal the production of multiple diverse types of opaque col- oured glass. However, it is generally considered that these types were mostly used for the manufacture of canes, beads, imitation gemstones, enamels and mosaic tesserae and to a much lesser degree for the pro- duction of vessel glass (Verit` a 2013). More specifcally, in Venice several specialized types of opaque glass were invented, such as lattimo (white opaque glass), chalcedony (a veined glass which could present various colours, such as purple, brown, red, blue and yellow, in imitation of zoned agate and jasper), aventurine (glass with small foliated, shining copper crystals), and girasole (glass which shows milky, pale blue colour in refected light and reddish to orange-yellow colour in transmitted light) (Neri and Merret 2011; Verit` a and Zecchin 2007). In Bohemia, in the early 18th c. a special type of opaque glass, named hyalith, was invented, which was initially black coloured and later on red and reddish-brown (Langhamer 2003). Despite the mutlitude and variety of * Corresponding author. E-mail address: el.palamara@gmail.com (E. Palamara). Contents lists available at ScienceDirect Journal of Archaeological Science: Reports journal homepage: www.elsevier.com/locate/jasrep https://doi.org/10.1016/j.jasrep.2023.104145 Received 15 May 2023; Received in revised form 22 July 2023; Accepted 24 July 2023