Gold, English mineral (3)
I believe the answer is:
ore
'mineral' is the definition.
(ore is a kind of mineral)
'gold english' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'english' becomes 'e' (abbreviation).
'or'+'e'='ORE'
(Other definitions for ore that I've seen before include "Metal-bearing rock or mineral" , "Raw metal" , "tangle" , "Rock from which metal is extracted" , "Mineral-bearing rock" .)