The Cistercian glazed tiles of the Monastery of Alcobaça: characterization of the colour palette

A rare medieval color palette was identified in the glazed tiles of Alcobaça Monastery, representing some of the earliest examples of tin-opacified glazes in Christian Portugal. The study found that the variety of colors—white, turquoise, brown, and shades of green—arose from different proportions of CuO, Fe2O3, and SnO2 within a lead-glazed matrix, combined with a K-feldspar-rich slip layer. This technology reflects a fusion of Cistercian traditions and Islamic tin-glazing techniques introduced to the Iberian Peninsula in the 10th century. Analytical methods including µ-PIXE, µ-Raman spectroscopy, and optical microscopy were used to characterize the tiles' chemical composition, providing insights into their historical significance.

Carvalho, F., Coentro, S., Costeira, I., Trindade, R. A. A., Alves, L. C., da Silva, R. C., & Muralha, V. S. F. (2016). The Cistercian glazed tiles of the Monastery of Alcobaça: characterization of the colour palette. Journal of Medieval Iberian Studies, 8(2), 196–216. https://doi.org/10.1080/17546559.2016.1222447