Travertine is a form of limestone deposited by mineral springs, especially hot springs.

It is sometimes known as travertine limestone or travertine marble; these are the same stone, although travertine is classified properly as a type of limestone, not marble. The stone is characterised by pitted holes and troughs in its surface. Although these troughs occur naturally, they suggest signs of considerable wear and tear over time. It can also be polished to a smooth, shiny finish, and comes in a variety of colors from grey to cream to coral-red. Travertine, in modern architecture, is most commonly available in tile sizes for floor installations but also for wall cladding and facades.

In Italy, well-known travertine quarries exist in Tivoli and Guidonia Montecelio, where the most important quarries since Ancient Roman times, like the old quarry of Bernini in Guidonia, can be found.

The latter has a major historic value, because it was one of the quarries that Gian Lorenzo Bernini selected material from to build the famous Colonnade of St. Peter’s Square in Rome (colonnato di Piazza S. Pietro) in 1656-1667. Michaelangelo also chose travertine as the material for the external ribs of the dome of St Peter’s Basilica.

Travertine derives its name from the former town, known as Tibur in ancient Roman times. The ancient name for the stone was lapis tiburtinus, meaning tibur stone, which was gradually corrupted to travertine

The Romans mined deposits of travertine for building temples, aqueducts, monuments, bath complexes, and amphitheaters such as the Colosseum, the largest building in the world constructed mostly of travertine