Scientists have identified the precise origin of the marble block used for Michelangelo's David, and say the discovery will be useful for helping to preserve one of the world's greatest sculptures. Until now, art historians knew only that the large block came from the Carrara quarries in Tuscany, which still produce many types and qualities of marble.

Analysts have now used three tiny samples, retrieved from the second toe of the left foot of David when the figure was damaged in act of vandalism in 1991, to track down the marble's origin. Not only were they able to determine the exact spot of excavation - the Fantiscritti quarries in Miseglia, the central of three small valleys in Carrara - they also found that Michelangelo's marble is of mediocre quality, filled with microscopic holes, and likely to degrade faster than many other marbles.