Micro‐Raman study of Medieval Cistercian 12–13th century manuscripts: Santa Maria de Alcobaça, Portugal

A Micro-Raman study of 12–13th century manuscripts from the Monastery of Alcobaça, a UNESCO World Heritage Site and Cistercian monastery founded in 1153, reveals distinct medieval color palettes characterized by consistent use of pink (vermilion or organic red mixed with lead white) and grey (carbon-based black pigment with lead white). Lazurite was the primary blue pigment, while azurite appeared only in one manuscript. Green hues were identified as bottle green, likely verdigris, showing signs of degradation. The study also detected darkening in lead white pigments, linked to galena formation and arsenate-based species, suggesting orpiment's role in degradation. Experimental validation confirmed these findings, indicating the presence of a new lead carbonate phase.

Muralha, V. S. F., Miguel, C., & Melo, M. J. (2012). Micro‐Raman study of Medieval Cistercian 12–13th century manuscripts: Santa Maria de Alcobaça, Portugal. Journal of Raman Spectroscopy, 43(11), 1737–1746. Portico. https://doi.org/10.1002/jrs.4065