Mineralogical and chemical characterization of surfa ce orange layers on the limestone of the Monastery of Batalha, Central Portugal

A mineralogical and chemical analysis of orange surface layers on the limestone balustrades and sculptures of the Monastery of Batalha, Portugal, reveals that these patinas are primarily composed of gypsum and hematite, with minor components including halite and weddellite. This finding challenges the assumption that such patinas form naturally through weathering, suggesting instead that they may have been intentionally applied for protective or aesthetic purposes. The study employed X-ray micro-diffractometry (µ-XRD) and low-vacuum scanning electron microscopy coupled with energy-dispersive spectrometry (LV-SEM + EDS) to characterize the layers. These results are compared to 'scialbatura,' a common protective coating used in monument conservation, providing insights into potential historical techniques for stone preservation.

Ding, Y., Redol, P., Angelini, E., Mirao, J., & Schiavon, N. (2020). Mineralogical and chemical characterization of surfa ce orange layers on the limestone of the Monastery of Batalha, Central Portugal. https://doi.org/10.5281/ZENODO.4894134