Buffer material (5)
I believe the answer is:
emery
'buffer material' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for emery that I've seen before include "Dick - - , late comedian" , "Black abrasive" , "Abrasive powder" , "Rock used as abrasive" , "Coating on paper used as an abrasive" .)