This is the final peer-reviewed accepted manuscript of: Enrico Sassoni, Gabriela Graziani, Elisa Franzoni, George W. Scherer Conversion of calcium sulfate dihydrate into calcium phosphates as a route for conservation of gypsum stuccoes and sulfated marble. Construction and Building Materials, Vol. 170 (2018), p.290-301 The final published version is available online at: https://doi.org/10.1016/j.conbuildmat.2018.03.075 © 2018. This manuscript version is made available under the Creative Commons Attribution- NonCommercial-NoDerivs (CC BY-NC-ND) 4.0 International License (https://creativecommons.org/licenses/by-nc-nd/4.0/)