Pietra Alberese: from traditional building material of the Tuscan countryside to the present use (Tuscany, Italy)

In Tuscany, the vernacular architecture of the countryside between Siena and Florence (Chianti territory), and the monumental architecture of towns such as Prato and Pistoia together with the surrounding villages, extensively used a local limestone, the Pietra Alberese. It is a grey marly limestone, very resistant to decay, which takes on a whitish colour upon exposure to atmospheric agents. In addition, the Pietra Alberese was used to produce lime, being the only limestone cropping out in this territory. In this work, the Pietra Alberese is characterized, from a geological, mineralogical and petrographic point of view, highlighting its problems of conservation. Furthermore, the use in the historical architecture (both vernacular and monumental) and in the twentieth century architecture is illustrated.