Estimation of the potential bioreceptivity of granitic rocks from their intrinsic properties

Where stone is a part of cultural heritage, knowledge of the potential bioreceptivity of the type of rock before use in a monument or any building would be particularly useful. In this study, it was demonstrated that bioreceptivity of granitic rock differs with the variety, because of the differences in some intrinsic properties. In addition, differences in surface finish result in differences in the relationship of the rock with water, and hence in the bioreceptivity of the rock. Taking into account these findings, a rapid and easy test was developed for investigating the potential bioreceptivity of granite to phototrophic organisms, cyanobacteria. Potential bioreceptivity can be evaluated before rocks are exposed to environmental conditions by determining the following four intrinsic properties: abrasion pH, bulk density, open porosity and capillary water. All these properties are easy to determine and the methodology is well established.