Talc /(tălk)/

Talc

n.
  1. A soft mineral of a soapy feel and a greenish, whitish, or grayish color, usually occurring in foliated masses. It is hydrous silicate of magnesia. Steatite, or soapstone, is a compact granular variety. (Min.)

Phrases & Compounds
Indurated talc
an impure, slaty talc, with a nearly compact texture, and greater hardness than common talc; -- called also talc slate.