talc 
(t
ălk)
n. A fine-grained white, greenish, or gray mineral, Mg3Si4O10(OH)2, having a soft soapy feel and used in talcum and face powder, as a paper coating, and as a filler for paint and plastics.
tr.v. talcked,
talck·ing,
talcs or
talced or
talc·ing To apply this substance to (a photographic plate, for example).
[French, from Medieval Latin talcum and Old Spanish talco, both from Arabic ṭalq, from Persian talk.]