A number of surface-treatment methods can be used to increase the rock roughness to improve its antislip properties while preserving aesthetic appearance. Bush hammering and water jetting are two of these surface-treatment methods. In this study, Sardinian basalt samples were treated with plain water jet and soft and hard bush-hammering methods, and quality of surfaces treated was assessed geostatistically. Realizations of the treated surfaces were generated by using sequential Gaussian simulation. The results show that the surfaces treated by the water-jet method are more homogeneous than others.