Archaeometric analysis of Nasrid glazed architectural ceramics from the Alhambra and Generalife Monument, Granada (Spain)

This work presents the first systematic archaeometric data of 13th–14th century AD Nasrid glazed architectural ceramics from the Alhambra and Generalife, focusing on colour-specific glazing technologies. Findings provide new insights into Nasrid glazing technology, ceramic typologies, and conservation implications, contributing to discussions on Islamic material culture and technical traditions in al-Andalus. Analysed typologies include mosaic, inlay, relief tiles, roof lights, and steles with glazes in white, blue, green-turquoise, black, and honey tones. Microstructural and chemical results reveal decorative chromophores and techniques to be a reference for future studies. Most glazes are inglaze on lead tin-opacified bases, fired in oxidising conditions at ∼950 °C. Phosphorus was found in weathered glazes (associated with a burial environment) and unweathered white and blue glazes, suggesting deliberate addition of bones (fragments/ashes). Identified phases in most glazes were unmelted quartz and feldspars grains, and relatively abundant Cr-bearing wollastonite crystals precipitated during firing. Furthermore, one of the fragments with a black surface was determined not to be a glaze, but rather a polished section of a metamorphic rock.