DESCRIPTION
Travertine is a limestone formed by evaporative precipitation, often forming such formations as stalactites, stalagmites, and flowstone such as the massive terraces at Mammoth Hot Springs in Yellowstone National Park. Its color ranges from gray to coral red and it is used frequently for flooring, façades, and wall cladding. The Romans used it to build many structures, and the Colosseum is one of the largest buildings that uses it primarily. Michelangelo used it for the external ribs of the Basilica of St. Peter’s Square.