Chalk is a fine-textured, earthy type of limestone distinguished by its light colour, softness, and high porosity. It is composed mostly of tiny fragments of the calcite shells or skeletons of plankton, such as foraminifera See more

Chalk is mined from chalk deposits both above ground and underground. Chalk mining boomed during the Industrial Revolution, … See more

• Blackboard – Reusable writing surface
• Chalk carving – Method of shaping chalk
• Chalk line – Tool for marking straight lines
• Chalk stream – Rivers rising from chalk bedrock See more

In Western Europe, chalk was formed in the Late Cretaceous Epoch and the early Palaeocene Epoch (between 100 and 61 million years ago). It … See more

Chalk is so common in Cretaceous marine beds that the Cretaceous Period was named for these deposits. The name Cretaceous was derived from Latin creta, meaning chalk. Some deposits of chalk were formed after the Cretaceous.
The See more

Most people first encounter chalk in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to … See more

• Gordon, Helen (23 February 2021). "Rock of ages: How chalk made England". The Guardian. Adapted from Notes From Deep Time: A … See more