Travertine Rock

It is a terrestrial counterpart of tufa.





It forms when calcium carbonate precipitates from hot springs and ground and surface water solutions.

It has a concentric or fibrous habit.

 
 By Al_HikesAZ via Flickr.com

It is naturally white, but often strained brownish, reddish or yellow by impurities such as iron oxides and others.

 
 By Frank Kovalchek via Flickr.com 

Its main minerals are calcite and aragonite.

  
 By Don Graham via Flickr.com

Small organisms such as cyanobacteria, algae and others often live on its surface, which causes the porosity.

 
 By vtveen via Flickr.com

Like tufa, it also has a siliceous version called siliceous slinter.

 
 By seier+seier via Flickr.com

It has been widely used as building material, both in buildings and facades, and inside the buildings such as in tiles and floor installations.

  
 By Darkroom Daze via Flickr.com

Some famous buildings built from this rock are Sacre Coeur in Paris and Colosseum in Rome.

 
 By Darkroom Daze via Flickr.com