Chalk

Chalk is a soft form of the mineral calcium carbonate. Chalk can be found in many places, including:

In the United Kingdom:

On the Sussex coast:

• At Beachy Head
• At Eastbourne
• At the famous white cliffs[?] of Dover

In the United States:

• In the extensive Austin Chalk formation, which underlies much of central Texas

The substance known as "blackboard chalk", often supplied in sticks about 2 inches (or 5 cm) long and used for drawing, especially on a blackboard, is not actually chalk: it is made from gypsum, calcium sulfate. Similarly, the "chalk" used by tailors is usually made from talc, magnesium silicate.

See also: List of minerals