<Tr> <Th_colspan="2"> Composition </Th> </Tr> <Tr> <Td_colspan="2"> Calcium carbonate: inorganic crystalline calcite and / or organic calcareous material </Td> </Tr> <P> Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs . Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO). </P> <P> About 10% of sedimentary rocks are limestones . The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years . Most cave systems are through limestone bedrock . </P>

Calcite is the main mineral found in which of the following rocks