Calcium carbonate Limestone quarries:
Calcium carbonate Have you ever seen the 'white cliffs of Dover? If you have, you've seen lots of calcium carbonate. Chalk is one form of limestone, made from around 98% calcium carbonate. You might also find other rocks containing calcium carbonate around your school Limestone itself is a common building material. It might be spread on the school roads or roofs as chippings. Chalk is one form of limestone, made from around 98% calcium carbonate. The chemical formula of calcium carbonate is CaCO 3 . Another source of calcium carbonate is marble. Another source of calcium carbonate is marble. The chemical formula of calcium carbonate is CaCO 3 . Many rocks with calcium carbonate in them were formed from the shells of sea creatures that died millions of years ago. The sediments built up on the seabed and slowly formed limestone. Marble is formed from limestone crushed by powerful movements in the Earth's crust and/or by very high temperat