From the physical-geological point of view, the municipal territory has a mixture of clays and sands of Pienocene ranging from 300 to more than 700 feet high.
Behind the main town stands a basalt cliff volcanic cone, whose formation took place between 1.300 000 and 970.000 years ago.
The cliff reaches 896 meters and dominates the valleys below that form the basin of Radicofani, the first formation of the volcanic area (Amiata also a volcano and formed 300,000 years ago); the volcanic vent formed of rocks of trachi-basalts, had collapsed several times and its meltdowns have formed at its foot, large areas of boulders.
To date the cliff is what remains of the central duct. From the geological point of view the rocks of Radicofani have a lot of particularity so much as in 1887 G.Mercalli wrote a famous article "le Lave di Radicofani" (The Lave of Radicofani) published in a scientific journal of that time.