Limestone is a soft, fine-grained, sedimentary rock that consists of calcite minerals (calcium carbonate). It is composed mainly of marine life sediment such as secretions and skeletal fragments, and often contains complete fossils. The limestone around Amman formed in shallow reefs between 250 and 25 million years ago. Limestone is usually white, but can be tinted by additional organic and mineral content. Chalk is a very soft limestone composed of microscopic organisms. The Dead Sea region produces color-banded limestone resembling marble called Travertine, which might have formed in hot springs from evaporating mineral-rich water. Limestone fizzes in vinegar and dissolves in stronger acids, making it vulnerable to pollution and acid rain.
Common in western Jordan, including Amman, Ajloun, Karak, Ma’an, and Hallabat (east of Zarqa). Widely used as a building stone in Jordan, and to manufacture lime and cement.