(a)
(b)
Figure 12: (a) Treatment of nanolime on limestone from Puerto de Santa María (Cádiz, España). Ca(OH)2 nanoparticles enter in stone and consolidate the grains. (b) Layer of silica nanoparticles over the surface of limestone from Espera (Cádiz, España), showing the incompatibility of the treatment with this kind of limestone.