Travertine

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Travertine is a form of limestone deposited by mineral springs, especially hot springs. Travertine often has a fibrous or concentric appearance and exists in white, tan, and cream-colored varieties. It is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot spring or in a limestone cave. In the latter, it can form stalactites, stalagmites, and other speleothems. It is frequently used in Italy and elsewhere as a building material.


Travertine is a terrestrial sedimentary rock, formed by the precipitation of carbonate minerals from solution in ground and surface waters, and/or geothermally heated hot-springs.[1][2] Similar (but softer and extremely porous) deposits formed from ambient-temperature water are known as tufa.


Travertine forms from geothermal springs and is often linked to siliceous systems that form siliceous sinter. Macrophytes, bryophytes, algae, cyanobacteria, and other organisms often colonise the surface of travertine and are preserved, giving travertine its distinctive porosity.


Some springs have temperatures high enough to exclude macrophytes and bryophytes from the deposits. As a consequence, deposits are, in general, less porous than tufa. Thermophilic microbes are important in these environments and stromatolitic fabrics are common. When it is apparent that deposits are devoid of any biological component, they are often referred to as calcareous sinter.


Travertine is often used as a building material. 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.


Travertine is one of the most frequently used stones in modern architecture. It is commonly used for façades, wall cladding, and flooring. The lobby walls of the modernist Willis Tower (1970) (formerly Sears Tower) in Chicago are made of travertine.[14] Architect Welton Becket frequently incorporated travertine into many of his projects. The first floor of the Becket-designed UCLA Medical Center has thick travertine walls. Architect Ludwig Mies van der Rohe used travertine in several of his major works, including the Toronto-Dominion Centre, S.R. Crown Hall and the Farnsworth House.