Stone composed mainly of calcium carbonate, much of it sedimentary rock and formed by fossil deposits. Marble is actually a limestone that can be polished.Examples of works in limestone: Egypt, c. 2620-2350 BCE (4th or 5th Dynasty), The Seated Scribe, Sakkara, painted limestone statue, 53.7 x 44 x 35 cm, Louvre. See Egyptian art and polychrome.