Soapstone (4)
I believe the answer is:
talc
'soapstone' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for talc that I've seen before include "Toilet powder - mica" , "I may dust" , "Scented powder used after bathing" , "Drier" , "Fragrant powder" .)