GEOLOGY & PLANETARY SCIENCE A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site limestone Limestone. Credit: Mineral Information Institute A sedimentary rock composed mainly of calcium carbonate (CaCO3) and magnesium carbonate (MgCO3). The chief minerals found in limestone are calcite and aragonite; dolomite is also be present in the dolomitic limestones. Of the many varieties of limestone most have been deposited in shallow water. Organic limestones (e.g. chalk) are formed from the calcareous skeletons of marine organisms. Precipitated limestones include oolite, which is composed of ooliths – spherical bodies formed by the precipitation of carbonate around a nucleus. Clastic limestones are derived from fragments of pre-existing calcareous rocks. Limestone is used as building stone, and in the manufacture of lime, carbon dioxide, and cement. Related category    • GEOLOGY AND PLANETARY SCIENCE Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP