Trying experience in gold trade (6)
I believe the answer is:
ordeal
'trying experience' is the definition.
(I've seen this before)
'gold trade' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'trade' becomes 'deal' (synonyms).
'or'+'deal'='ORDEAL'
'in' is the link.
(Other definitions for ordeal that I've seen before include "Suffering - trial" , "Difficult or arduous experience" , "very hard test" , "Struggle" , "A difficult or harrowing time" .)