from
The Collaborative International Dictionary of English v.0.48
Talc \Talc\ (t[a^]lk), 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.
[1913 Webster]
{Indurated talc}, an impure, slaty talc, with a nearly
compact texture, and greater hardness than common talc; --
called also {talc slate}.
[1913 Webster] Talcose