SEM-FEG-EDS, GC-MS, EPR and Vibrational Spectroscopy Analysis of Materials in Baroque-Style Sculpture “Our Lady of Sorrows” from Garopaba, Santa Catarina, Brazil

Abstract

Materials belonging to the polychromy and gilding of the sculpture ‘Our Lady of Sorrows, which belongs to the collection of a church in Garopaba, Santa Catarina, southern Brazil, were analyzed by multiple techniques. The analysis by μ-Raman and FTIR indicated the use of the ultramarine blue pigment, confirmed by EDS, with calcium carbonate observed in the base of preparation. The results show the use of gold leaf based on a gold and silver alloy, and the use of Armenian bole with clay and traces of manganese, as the base for fixing the gold leaf was characterized. GC-MS analysis suggested the use of plant oil in the painting process. Finally, the EPR analysis showed the presence of Fe3+, Mn2+ and organic radicals from the degradation of the binder, suggesting the formation of complexes with the degradation products, this being one of the first reports in this type of painting.