Briquettes, eventually (5)
I believe the answer is:
ashes
'briquettes eventually' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ashes that I've seen before include "Test-match trophy" , "Remains of anything burnt" , "Remains from a cremation" , "Residue from fire" , "''... to ..., dust to dust'' (burial service)" .)