 Complete the following phrase:  Marble intarsia opere di commessi, called pietre dura in English for the semi-precious hardstones combined with colored marbles that are employed, is an intarsia of coloured stones inlaid in white or black marble. Early examples in Florence date from the mid fifteenth century and reached a peak of refinement and complexity in revetments of the Medici Chapel, produced under Medici patronage in the Opificio delle Pietre Dure, which was established by Ferdido I de Medici. Later complex designs and refinement of the art developed in Naples circa the beginning of the 17th century. The floor of St. Peters Basilica in Rome is a particularly notable example of marble intarsia. Later this form of decoration became a feature of baroque interior design, particularly so in the Sicilian Baroque designs following the 