At number 78 of Via degli Alfani, in the San Marco district, in the heart of the city, about 400 m from Santa Maria del Fiore, is the Semi-precious Stone Workshop (the Opificio delle Pietre Dure, also known by its initials: OPD) which must absolutely not be missed.
It is actually an independent institute in the Ministry for Cultural and Environmental Assets, and its operations and research are in the field of art work restoration.
The museum is famous throughout the world for working semi-precious stones, and it offers a surprising view of this ancient Renaissance art, which was necessary to decorate the churches and elegant seigniorial palaces, such as, for example, the Medici crypt.
It was founded in 1588 in what was previously the San Niccolò convent, on the wishes of Ferdinando I de' Medici, for the manufacture of works and furnishings in semi-precious stones, an art known as commesso fiorentino, by which splendid inlaid work with semi-precious stones is still carried out today.
At the end of the XIX century, when there was no longer a demand for the production of furnishings commissioned in semi-precious stones, the factory was turned into a restoration workshop.
After the terrible flood in November 1966 and the law passed in 1975 which created the Ministry for Cultural and Environmental Assets, all the State restoration workshops of Florence, except those regarding architectonic and archaeological works, were annexed to the historic factory.
Today the Institute is divided into three sectors, corresponding to the different materials in which the works of art are made. It is also the seat of a Higher Training School awarding a diploma equivalent to a university degree, of a museum and of a library highly specialised in the restoration sector. The museum is open to the pubic every day except Sundays and national holidays.