Limestone - GCSE Chemistry Definition

Limestone is a type of sedimentary rock that is mainly made up of calcium carbonate, (CaCO₃), which comes from the remains of sea creatures that lived millions of years ago. This rock forms in clear, warm, shallow marine waters, and is often found in areas where ancient seas used to exist. Limestone is important because it is used to make cement and concrete, and it is also a common building material used in walls, floors, and sculptures. In chemistry, limestone is significant because it reacts with acids, producing carbon dioxide gas, and can be heated to produce quicklime (calcium oxide) in a process called thermal decomposition.