Burning torch an essayist coated in iron and gold (8)
I believe the answer is:
flambeau
'burning torch' is the definition.
(I've seen this before)
'an essayist coated in iron and gold' is the wordplay.
'an essayist' becomes 'lamb' (I've seen this before).
'coated in' means one lot of letters goes inside another.
'iron' becomes 'Fe' (Fe is the chemical symbol for iron).
'and' is a charade indicator (letters next to each other).
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'lamb' placed inside 'fe' is 'flambe'.
'flambe'+'au'='FLAMBEAU'
(Other definitions for flambeau that I've seen before include "Old blazer" , "Torch; candlestick" , "Flaming torch" , "Burning torch" , "One may be burning" .)