The alabaster, formed in the territory of Volterra during the Miocene period from the concentration of marine salt, in particular chloride of sodium and sulfate of calcium, is a candid stone sometimes marked with stripes, variously opaque and much more softer than marble, which makes it easy to create sculptures rich in details and luminous objects.

The alabaster is extracted in blocks of oval shape in galleries deep from 50 to 100 meters situated in Castellina Maritima or in opened sky caves in the communes of Pomarance, Gesseri and Ulignano.