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<p class="Abstract">To assess the provenance of the limestones used in the construction and restoration of the Batalha Monastery in central Portugal, stone samples collected from the monument and from five limestone quarries in the region surrounding the building were investigated by energy-dispersive X-ray fluorescence spectroscopy (ED-XRF), powder X-ray diffractometry (PXRD) and thermogravimetric analysis (TGA). Ca-Sr binary diagrams from the ED-XRF result indicated the source of the samples collected from different parts of the monastery. Thin-section observation supplemented the petrographic evidence for this identification. PXRD and TGA were also used to acquire information on the mineral and chemical composition of the stones. Preliminary results suggest that the monastery baluster was made of stone from the Valinho do Rei or Reguengo do Fetal quarries, whereas part of the church railing, the north-aisle eaves arch and Royal Cloister were made with stone from the Pidiogo or Cabeço do Roxo quarries.</p>

This work presents the results of the exposure of soda-lime, potash-lime and mixed-alkali silicate glasses during ten and twenty months in different Portuguese monuments with historical stained-glass windows to characterize the influence of local environmental conditions. The glass samples were exposed in the Monastery of Batalha (Batalha), the Monastery of Jerónimos (Lisbon), and the Cathedral of Évora (Évora). A set of analytical techniques to assess the physicochemical effects were used, including optical microscopy and Fourier transform infrared spectroscopy. All the samples presented crystalline deposits on their surface; however, their quantity and nature depended on the atmospheric conditions during the days before the collection. Potash-lime silicate glass was the most altered glass in comparison with soda-lime and mixed-alkali silicate glasses. The samples from the Cathedral of Évora showed a high content of dust and salts on their surface but without severe chemical pathologies; however, those samples exposed in the Monastery of Jerónimos and the Monastery of Batalha presented alteration layers due to a high humidity environment.

Samples of orange patinas found on a limestone window tracery and an ornament of the Batalha Monastery have been investigated by X-ray micro-diffractometry (μ-XRD) and low-vacuum scanning electron microscopy coupled with energy dispersive spectrometry (LV-SEM + EDS). The aim of the study was to determine the composition of the layered patinas, assess whether they have been intentionally applied or naturally formed, and study their degradation patterns. Preliminary results revealed that the orange patinas on the window tracery and the ornament showed different compositions and appearance, suggesting distinct formation pathways. Orange patinas on the ornament, which are now showing decay and delamination patterns, mainly consisted of gypsum with hematite as a minor component, implying the possibility of an intentional application of a mixture of ochre and lime as tint plaster. Orange patinas on the window tracery show, instead, the presence of Ca-oxalates, abundant weddellite, and minor whewellite, with minor hematite suggesting the yellowish/orange color as being due to Ca-oxalate patinas imbedding soil dust airborne particles. Such patina was possibly formed naturally either by the chemical attack due to atmospheric air pollutants from traffic exhausts emissions or by bacterial activity. No delamination was observed on the window tracery sample with granular decohesion as the major decay phenomenon. A comparison was made between this patina and the so-called scialbatura, a surface yellowish coating often found by conservators on limestone and marble in ancient monuments in the Mediterranean region.

Samples of orange patinas found on a limestone balustrade and an ornament of the Batalha Monastery have been investigated by X-ray micro-diffractometry (µ-XRD) and Low-Vacuum Scanning Electron Microscopy coupled with Energy Dispersive Spectrometry (LV-SEM + EDS). Aim of the study was to determine the composition of the layered patinas, assess whether they were been intentionally applied or naturally formed, and study their degradation patterns. Preliminary results revealed that the orange patinas on the balustrade and the ornament showed different compositions and appearance, suggesting distinct formation pathways. Orange layers on the ornament which suffers salt decay and delamination nowadays, mainly consisted of gypsum with hematite as a minor component, implying the possibility of an intentional application of a mixture of ochre and lime as tint plaster. Orange patinas on the balustrade show the presence of Ca-oxalates, abundant weddellite and minor whewellite, with minor hematite suggesting the yellowish/orange color to be due to Ca-oxalate patinas imbedding soil dust airborne particles. Such patina was possibly formed naturally either by the chemical attack due to atmospheric air pollutants from traffic exhausts emissions or by bacterial activity. No delamination was observed, abrasion is the major decay phenomenon on the balustrade sample. A comparison was made between this patina and the so called “scialbatura”, a surface yellowish coating often found by conservators on limestone and marble in ancient monuments in the Mediterranean region.