Iron or gold (5)
I believe the answer is:
metal
I believe this clue is a double definition.
'iron' is the first definition.
(I've seen this before)
'gold' is the second definition.
(thesaurus)
(Other definitions for metal that I've seen before include "Tungsten, for example" , "Zirconium, for example" , "Alloy" , "Eg, Iron or gold" , "Iron, for instance" .)