The Collaborative International Dictionary of English v.0.48:

Talcose \Tal*cose"\ (t[a^]l*k[=o]s" or t[a^]lk"[=o]s`), Talcous
\Talc"ous\ (t[a^]lk"[u^]s), a. [Cf. F. talqueux.] (Min.)
   Of or pertaining to talc; composed of, or resembling, talc.
   [1913 Webster]