pietra dura

Pietra dura is Italian for 'hard stone.' The technique — cutting and fitting thin slices of semiprecious stone (lapis lazuli, malachite, jasper, agate, onyx, mother-of-pearl) into mosaic-like pictures or patterns — was perfected in Florence in the sixteenth century. The Medici Grand Dukes established the Opificio delle Pietre Dure in 1588, a state workshop that still operates today. The workshop's name is its own description: a factory for hard stones.

The technique requires cutting each stone piece to fit against its neighbors with no visible gap. The stones are sawn to a thickness of about 3 millimeters, then shaped by hand using a bow saw and abrasives. A single tabletop of pietra dura might contain hundreds of individually cut pieces of twenty different stones. The colors are the natural colors of the minerals: the green of malachite, the blue of lapis lazuli, the red of carnelian. No paint. The palette is geology.

The Moguls adopted pietra dura — or parchin kari, as they called it — and applied it to architecture. The Taj Mahal's exterior and interior surfaces are inlaid with flowers and abstract patterns in semiprecious stone. Italian craftsmen may have been among the workers — there is documentary evidence of European artists at the Mughal court. Whether the technique arrived from Florence or developed independently in India is debated. What is not debated is that the Taj Mahal is the largest and most famous pietra dura surface in the world.

The Opificio delle Pietre Dure in Florence still trains restorers and produces new work. The institution has been in continuous operation for over 435 years. The stones have not changed. The saws have not changed. The patience required has not changed. A tabletop might take a craftsman two years. The Medici thought that was a reasonable exchange for permanence.