The Opificio delle pietre dure, literally meaning Workshop of semi-precious stones, is a public institute of the Italian Ministry for Cultural Heritage based in Florence. It is a global leader in the field of art restoration and provides teaching as one of two Italian state conservation schools (the other being the Istituto Superiore per la Conservazione ed il Restauro). The institute maintains also a specialist library and archive of conservation and a museum displaying historic examples of pietre dure inlaid semi-precious stones artefacts.