Travertine
Travertine is a very porous sedimentary limestone, formed by the deposition of calcium carbonate and the subsequent decomposition of the vegetal components incorporated in the mass. It is by no means unusual to find imprints of plant and animal fossils. Incorporated oxides can give travertine colors ranging from milk white to walnut, passing through various shades from yellow to red. This material has reasonable mechanical properties and is widely used in buildings, since low hardness means it is very easy to work.