Travertine is a sedimentary rock. It is a natural chemical precipitate of carbonate minerals; typically Aragonite, but often recrystallized to or primarily Calcite. Basically, calcium carbonate is deposited from the water of mineral springs or rivulets saturated with calcium bicarbonate. The spring water can either be hot, warm or cold. The amount of deposits may increase with the water's temperature or when biotic material accelerates the precipitation. The ornate columns of travertine in caves is one example of an inorganic chemical sedimentary rock.