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, cream-colored, grey to coral-red, & even rusty varieties. It is frequently used as a building material. Travertine is one of several natural stones that are used for paving patios and garden paths. The stone is characterized by pitted holes and troughs in its surface. Although these troughs occur naturally, they suggest signs of considerable wear and tear over time.