Abrasive powder (5)
I believe the answer is:
emery
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">abrasive powder</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 emery that I've seen before include "Hard black-grey mineral used in grinding and polishing" , "Coating on paper used as an abrasive" , "Abrasive form of corundum" , "Abrasive material" , "Hard, grey-black mineral used as 11 down" .)