Answer:
CaCO3
Step-by-step explanation:
Pure calcite has the composition CaCO3. However, the calcite in limestone often contains a few percent of magnesium. Calcite in limestone is divided into low-magnesium and high-magnesium calcite, with the dividing line placed at a composition of 4% magnesium. High-magnesium calcite retains the calcite mineral structure, which is distinct from that of dolomite, MgCa(CO3)2.[18] Calcite can also contain small quantities of iron and manganese.[19] Manganese may be responsible for the fluorescence of impure calcite, as may traces of organic compounds