Limestone is a sedimentary rock composed mainly of calcium. Limestone slabs range from light to dark and color. The texture of Limestone varies from fine grain to smooth, fossil-bearing types that showcase a piece of history. Limestone, like Travertine, features beautiful Earth tones that provide great design flexibility. Limestone makes a beautiful fireplace hearth. Due to its Calcium-based make-up, Limestone has similar use and care characteristics to Marble.