The jewel of Florence, the Cathedral of Santa Maria del Fiore, is given its unique lustre by Carrara marble. Quarried in northern Tuscany, the marble is now in huge demand around the world as a luxury building material. Carlo Colombi, the commercial director of the company that runs Carrara's quarry, testifies to how new technology and increased demand has sped up extraction. "Before, we needed one week to cut one block. Now we need six hours”. Today, some 5 million tonnes of mountain are removed annually, irrevocably altering the unique resource. Some fear that ever-rising demand may lead to over-exploitation of this precious resource.