In the mixing of metals, it may be best mix copper, gold, silver, brass, but iron do not seem to be a good match with the gold, if you look at the character of both, one is basically made for war, and gold for beauty /healing, so to to mix them may not be the best idea. It run in the same way that if you do medicine with crows, you will never do medicine with an howl, just dont fit together, or a sheep and a wolf, couple of my friends were talking and feeling this iron gold mix and did not much care for it Then again if you like it please do it j 
josh