Comparing the bioremoval of black crusts on colored artistic lithotypes of the Cathedral of Florence with chemical and laser treatment

► Comparative studies of three different cleaning procedures for black crust removal. ► Biocleaning is compared with laser treatment and performed on colored stones. ► The chemical cleaning led to non-homogeneous crust removal. ► Laser cleaning is preferred on the extremely powdery and incoherent red substratum. ► Biocleaning is the most controllable and efficient process for sulfate removal.