Travertine is a type of limestone. It is also called calcium carbonate.
Travertine is created when minerals have dissolved in the ground water and then get moved by natural springs and rivers above ground. It is taken from quarries in large blocks and then cut down into smaller blocks.
It has been used for thousands of years in a few countries, but today travertine is used all over the world for flooring, countertops, backsplashes, and other surfaces where tile is preferred.