The Influence of Environment in the Alteration of the Stained-Glass Windows in Portuguese Monuments

Research reveals that environmental conditions significantly influence the alteration of stained-glass windows, with potash-lime silicate glass being the most susceptible to degradation. The study exposed soda-lime, potash-lime, and mixed-alkali silicate glasses in three Portuguese monuments—Monastery of Batalha, Monastery of Jerónimos (Lisbon), and Cathedral of Évora—for 10 and 20 months. Analysis using optical microscopy and Fourier transform infrared spectroscopy showed that crystalline deposits varied based on atmospheric conditions, with high humidity environments like those in Batalha and Jerónimos leading to more severe alteration layers. While the Cathedral of Évora exhibited dust and salt accumulation without severe chemical damage, the findings underscore the importance of environmental factors in preserving stained-glass heritage.

Palomar, T., Redol, P., Cruz Almeida, I., Pereira da Silva, E., & Vilarigues, M. (2018). The Influence of Environment in the Alteration of the Stained-Glass Windows in Portuguese Monuments. Heritage, 1(2), 365–376. https://doi.org/10.3390/heritage1020025