ABSTRACT
The province of Sondrio occupies an Alpine territory in the northernmost part of Lombardy, among igneous and metamorphic outcrops, sedimentary rocks are lacking. Igneous rocks (Granito di Dubino, Ghiandone, Serizzo and Granito di San Fedelino) geologically belong to the formation called “Plutone della Val Màsino e della Val Bregaglia”. The so-called Granito di Dubino is a diorite and went in use in the 1930s; the Granito di San Fedelino was employed for paving of the urban streets of Milan and other Lombard towns, thanks to its very high resistance to wear. Ghiandone (granodiorite) and Serizzo (diorite) have been appreciated since the Roman period for their excellent qualities.
The so-called Granito Galleggione and Granito tipo Valcundria are metamorphic rocks: the first one is a gneiss, the second one a migmatite. Other metamorphic rocks are serpentinite, Pietra Ollare, mainly used to make cooking pots, and Verde Spluga, coming from Chiavenna, on the western side of Valle San Giacomo.
