So I got some chemicals for a blue patina and dropped a cast bronze pendant in to soak overnight.
Next morning, it wasn't blue, but sparkly gold. The reflections move and sparkle in a very interesting way.
My guess is the acids in the patina revealed the crystalline structure of the metal in the casting.
I'm not a fan of the color gold, but for some people at a craft show this might work. Now to figure out a top coating so it doesn't oxidize. This one is coated with a proven coating for outdoor sculptures. Tomorrow I will wax it with the stuff the British Museum uses on their sculptures.
If that doesn't work, I have a liquid dip from Italy that when heated to a precise temperature, bonds with the surface to seal it and prevent oxidation.