Travertine is a sedimentary rock, essentially a variety of limestone, formed by the rapid precipitation of calcium carbonate. Travertine has a fibrous or concentric structure and is most often coloured white, beige, cream or rust red. The use of travertine as a building material began as early as the time of the Roman Empire. Nowadays, travertine is used for facade cladding slabs, interior decorative cladding, flooring slabs, steps, countertops and decorative elements.