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 institute maintains also a specialist library and archive of conservation and a museum displaying historic examples of pietre dure inlaid semi-precious stones artefacts. A scientific laboratory conducts research and diagnostics and provides a preventive conservation service.