travertine

Travertine is a form of limestone deposited by hot or mineral springs, formed when calcium-rich waters degas carbon dioxide and precipitate calcium carbonate as a porous, layered rock. It is microcrystalline to fibrous in texture and often shows banding or a mottled surface. The stone varies in color from white and cream to tans, browns, and pinks, depending on impurities such as iron oxides, clay, or organic material.

Formation and distribution: Travertine forms at the surface around springs, geysers, and in cavern walls where calcium carbonate precipitates from groundwater. In many places it creates terraces and crusts, for example Pamukkale in Turkey and Tivoli near Rome, while large quarries supply building stone. It occurs in Italy, Turkey, Iran, Mexico, Peru, and the United States.

Uses and properties: Travertine has long been used as a building material for facades, floor and wall tiles, pavers, and decorative elements. It polishes well but remains relatively porous and softer than many marbles or granites; sealing is common to limit water absorption and staining. It is moderately heat and weather resistant but can etch with acids and degrade under freeze-thaw cycles if untreated.

Care and maintenance: Clean with pH-neutral or mild soap solutions; avoid acidic cleaners; reseal as needed based on use.

Geology and terminology: Travertine is a sedimentary rock, a variety of limestone formed by precipitation of calcium carbonate from supersaturated waters. It is distinct from marble (metamorphic) and is related to other carbonate rocks such as carbonate speleothems.