Provenance, characterization and decay of a porous calcarenite of the Puglia region ('Pietra Gentile')

Conservation of the built heritage requires knowledge of the characteristics and use of the constituent materials and their state of conservation. Knowledge of the material's source is important for laboratory studies and stone replacement, but it also has historic-cultural significance with respect to the exploitation of stone resources in the past. In this sense, we present a study of 'Pietra Gentile', a traditional building material of southern Italy, through which we aimed to acquire knowledge concerning the quarries, characteristics of extracted materials, use and decay features within buildings. Ancient and active quarries were identified and the petrographical, chemical-mineralogical and physical features of the quarry materials were studied. The use of the stone was documented in many historic towns in the area, including monuments and minor buildings, and the main decay morphologies were detected by field activities and laboratory analyses. The high susceptibility of the stone to the actions of water and salts was highlighted. Field and laboratory data of quarries and artefacts were organized into a database as a source of knowledge useful for the evaluation, preservation and promotion of cultural heritage.