Inca Stone's coping is constructed of Peruvian Travertine. Peruvian Travertine is one of the only natural stones in the industry that can be used in water-line and submersible application in swimming pools. Being that our Peruvian Travertine has tested with 99.9% Calcium Carbonate, the most reliable and stable Calcium you can have in a natural stone, Muratic acids, chlorine, and saline pools do not effect our stone; unlike other natural stones, pre-cast, and concrete products.