Gold doesn't oxidize.
I used to work for a company that made massive chandeliers for hotels and restaurants and I used to muck in and help finish them if we were short staffed.
You can get gold leaf, bronze leaf, copper leaf etc. and it either comes as loose leaf or on transfer paper, we always used to use the loose leaf.
You need to be in a still environment, the slightest movement of air will catch the leaf and it will fold up.
I had a little leather pad on a handle with a shield around it to stop air movement catching the leaf, you'd pick the sheet or part sheet up with an artist's brush and lay it onto your backing.
We used to paint the light fittings with a base coat and then as it was 99% dry lay on the gold leaf.
I remember coming in from my tea break one day and some joker had unwrapped my Mars bar and gold leafed it, I still ate it!