Travertine

Travertine terraces at Mammoth Hot Springs, Yellowstone National Park

Calcium-carbonate-encrusted, yet growing moss, early stage of porous travertine formation.

Travertine is a terrestrial sedimentary rock. It is a natural chemical precipitate of carbonate minerals; aragonite or calcite. This happens from solution in ground and surface waters, and/or geothermally heated hot-springs.^[1]^[2] Similar (but extremely porous) deposits formed from ambient-temperature water are known as tufa.

The Colosseum built by the Romans, was made of travertine.

Travertine Media

Travertine terraces at Mammoth Hot Springs, Yellowstone National Park, in 2016
Tourists climb Dunns River Falls with the help of guides.
Badab-e Surt's stepped travertine terrace formations. This travertine owes its red colour terraces to iron carbonate.
Tufa and travertine sediments visible on the Una river bed.
Mausoleum submerged in a travertine pool at Hierapolis hot springs, Turkey
Tufa and travertine deposits on Krka National Park
Soda Dam, Jemez Mountains, New Mexico
Sacré-Cœur, Paris, (1875–1914)
Burghausen Castle, Europe's longest castle, is 1,000 years old and built mainly with travertine.

References

↑ Dictionary of geological terms, 1962. A Dolphin Reference Book
↑ A glossary of karst terminology, 1970. Geol. Surv. Water-Supply Paper 1899-K, U. S. Gov. Print. Off., Washington.

Travertine in a 400 year old wall of the castle Hohen Tübingen. The material is extremely hard and weatherproof. The cavities and impurities - remnents of small debris, scrub and biotic materials - make the rock porous and lightweight.

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[1] Dictionary of geological terms, 1962. A Dolphin Reference Book

[2] A glossary of karst terminology, 1970. Geol. Surv. Water-Supply Paper 1899-K, U. S. Gov. Print. Off., Washington.

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