@article{Silva Hermo_Prieto Lamas_Rivas Brea_Pereira Pardo_2010, title={Gypsum-induced decay in granite monuments in Northwestern Spain}, volume={60}, url={https://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/169}, DOI={10.3989/mc.2010.46808}, abstractNote={One of the most common forms of decay in granite monuments is the detachment of the superficial layer of the stone (plaques, plaquettes and scales). Previous studies of granite monuments in the northwest Iberian Peninsula revealed a direct relation between this type of weathering and the presence of calcium sulphate, and a mechanism whereby the salt causes this type of decay was suggested. In the present study, various hypotheses as regards the origin of the gypsum found in granite monuments are proposed. The study involved analysis of the contents of ions soluble in water, the results of X-ray diffraction analyses and the ratios of CaO/SO<sub>3</sub> in samples of stone, mortar and deposits collected from different monuments. It was concluded that in most cases the gypsum originated from old paintworks or/and from the joint mortars, although inputs from other sources cannot be discounted, as discussed}, number={297}, journal={Materiales de Construcción}, author={Silva Hermo, B. and Prieto Lamas, B. and Rivas Brea, T. and Pereira Pardo, L.}, year={2010}, month={Mar.}, pages={97–110} }