Natural stone is an important component of historical heritage (buildings and art objects such as sculptures or rock engravings), and it is still widely used in contemporary works. Soluble salts are the main erosive agent in the built environment, and we review here comparative studies that subject the same rock type to testing with different salt solutions. The results mostly support the accepted notion of the major impact of sodium sulphate, although there are some exceptions. The effects of sodium chloride and calcium sulphate deserve specific discussion given field information on the relevance of these specific salts in the built environment. We relate the information collected to the issues of risk assessment (considering both geochemical conditions and salt effects) and conservation interventions (highlighting the interest of tests that do not produce damage to susceptible materials) and present some methodological suggestions to avoid a case study culture.The Lab2PT-Landscapes, Heritage and Territory laboratory—UIDB/04509/2020
is supported by the Portuguese FCT—“Fundação para a Ciência e a Tecnologia”. The authors
also gratefully acknowledge the support of the CERENA (funded by a strategic project of the FCTUIDB/04028/2020) and the LAMPIST of the DECivil, Instituto Superior Técnico, University of
Lisbon, Portugal. The University Institute of Geology of the University of A Coruña (Spain) receives
support from the Xunta de Galicia from the program “Consolidación y estructuración de unidades
de investigación competitivas: Grupos de potencial de crecimiento” (ED431B 2018/47) and Redes de
investigación (R2017/008)
