[1] : The Collaborative International Dictionary of English v.0.48

talc \talc\ ta^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
see also:
steatite soapstone indurated talc talc slate 

Talc >> T Words
Talc, definition of term: Talc
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Indurated >> I Words
Indurated, definition of term: Indurated
indurated_pag1.html