Where Does Chalk Come From

Chalk is a variety of limestone composed mainly of calcium carbonate derived from the shells of tiny marine animals known as foraminifera and from the calcareous remains of marine algae known as coccoliths. Chalk is usually white or light gray in color.

Is chalk made of dead animals?

Chalk is composed of planktonic skeletons and is therefore made of micro-fossils. In fact, the coccolithophores that comprise chalk are small even by planktonic standards and are therefore termed nanno-fossils.

Can you eat chalk?

While chalk is minimally toxic, not poisonous in small amounts, and may not hurt you, it’s never a good idea to eat chalk. A pattern of eating chalk is a different story, however. Eating chalk often can disrupt your digestive system and cause damage to your internal organs.