Porous type of limestone resulting from deposition by springs or rivers. It is often beautifully colored and banded as a result of the presence of iron compounds or other impurities. When used for decorative purposes, it is also known as onyx marble. Travertine is generally less coarse-grained and takes a higher polish than stalactite and stalagmite, which are similar in chemical composition and origin.Cut all sides to full-dimension with a tumbled surface; Consistent thickness of 1". Often used for patios and pathways.