Historic ornamental stones from the Western Alps and their use in Cultural Heritage.

In Piedmont, the stone has always been the most widely used raw materials for buildings, characterizing the architectural identity of the city of Turin. The great variety of ornamental stones occurring in Turin is certainly due to the highly composite geological nature of Piedmont region related to the presence of the metamorphic Alpine chain and the sedimentary Tertiary Piedmont Basin. This research provides a list of the great variety of the historic and contemporary Piedmont ornamental stones, which have been used over the centuries in buildings and architecture. The main stones occurring in Turin were identified and studied by a petrographic and mineralogical point of view in order to find out the corresponding geological units and quarry sites. Multiple analytical techniques such as optical and scanning electron microscope, electron microprobe, cathodoluminescence and microfluorescence were used.