chalk

An amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant.

A piece of calcite or a similar substance, usually in the shape of a crayon, that is used to write or draw on blackboards or other flat surfaces.

A pure flat white with little reflectance.

A soft whitish calcite.

Write, draw, or trace with chalk.