Travertine Tiles : Travertine is generally filled with cement before it is honed or polished, which produces a uniform surface more like other marbles. Unfilled travertine is quite beautiful, and is often seen as exterior cladding on buildings. Travertines result from hot spring water percolating up through underground limestone. When the water evaporates, it leaves behind layers of dissolved limestone and other minerals, giving it its banded appearance. The characteristic holes in travertine are the result of trapped gas bubbles; as the gas escapes, crystals form in the cavities. Travertines are generally light-colored beiges and tans, though there are some beautiful, colored Travertines that have resulted from other minerals dissolved by hot water underground.