? Venetian chalk.

A massive variety of talc, of which various kinds are found in several countries, having a smooth greasy feel, and used for various economical or…

soapstone.

a hydrous silicate of magnesia.

Steatite; magnesian clay.

A massive variety of talc, commonly of a grey or greyish green colour, with an unctuous or soapy feel; soap-stone.

potstone, or soapstone.

A synonym of steatite, n. Obsolete.

= potstone, n. 1.

(see quots.).

(see quots.).