Current methods and future trends in testing, durability analyses and provenance studies of natural stones used in historical monuments

The paper summarizes the techniques available for in situ and laboratory testing of natural stones used in historical monuments by combining the results of previous studies and papers published in this volume. From diagnostic studies of decay forms via non-destructive to low-destructive on site test wide ranges of new techniques available for understanding the behaviour of stones under ambient conditions. Laboratory tests facilitate the identification of stones by using petrographic–mineralogical analyses and also allows understanding of the role of micro-fabric in durability. Rock mechanical properties also significantly influence the long-term durability of stones. Testing of responses of stones to external stress factors such as salt or thermal shock is also demonstrated in the published papers by presenting various scenarios and methods of ‘fatigue’ analyses. Finally, the need for a complexity of approaches in stone testing and limitations of available authentic stone resources are also covered.