Travertine is one of several natural stones that are used for paving patios and garden paths. It is sometimes known as travertine limestone, sometimes as travertine marble; these are the same stone, even though it is neither limestone nor marble. The stone is characterized by pitted holes and troughs in its surface. Although these troughs occur naturally, they suggest to some eyes that considerable wear and tear has occurred over many years. Some installers use a grout to fill these holes, whereas others leave them open — travertine can even be purchased "filled" or "unfilled." It can be effectively polished to a smooth, shiny finish and comes in a variety of colors from grey to coral-red. Travertine is most commonly available in tile sizes for floor installations.
Travertine is one of the most frequently used stones in modern architecture, and is commonly seen as facade material, wall cladding, and flooring. Architect Welton Becket was one of the most frequent users of travertine, incorporating it extensively into many if not most of his projects. The entire first floor of the Becket-designed UCLA Medical Center has thick travertine walls.
There are two or three small travertine producers in the western United States. U.S. demand for travertine is about 0.85 million tones, almost all of it imported. Most of the imports come from Turkey, Mexico is next, then Italy, and then Peru. A decade ago, Italy had almost a monopoly on the world travertine market.