The Collaborative International Dictionary
Indurated talc
Talc \Talc\, n. [F. talc; cf. Sp. & It. talco, LL. talcus; all fr. Ar. talq.] (Min.) 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.
Indurated talc, an impure, slaty talc, with a nearly compact texture, and greater hardness than common talc; -- called also talc slate.