Soft mineral (4)
I believe the answer is:
talc
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">soft mineral</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for talc that I've seen before include "Cosmetic powder" , "Toilet powder - mica" , "soother" , "Drier" , "Powdered substance" .)