Iron can be a complicated topic which could fill many books.
"I meant to also ask about already rusted iron being used as well.How much would that change the break down reaction? Is it possible in any way to drop gold from any of these iron states?"
I do not know what you are asking here, maybe if you re-phrase the question.
Or explain what you are doing and what your problem is, I am having a hard time trying to figure out what the question is, so it makes it hard for me to try and answer.
There are a couple of different forms of iron we call rust, one will dissolve in acids like chlorides or sulfates, and the other will not dissolve very well in any acid including aqua regia.
You will not have rust dissolved into your solution, and if you do then it is no longer rust, but would be an iron compound like iron chlorides or iron sulfate...
Iron can form many chemical complexes, iron oxides, hydroxides, and oxide-hydroides can also come in several different complexes, I could count more forms than I have fingers on my hands, and then we have iron ore compounds that can be forms of these and more.
Rust, well that is what we call our iron metal that gets oxidized by moisture and air, actually there are several chemical forms of rust, but two main ones come to my mind the two types of black rust which can be easily converted back to iron if we give it an electron, and the red rust which cannot easily be converted back to iron.
The black rust Iron II oxide (FeO).
The more common black Iron (II,III) oxide (Fe3O4) (magnetite ore) (magnetic).
And then we have the red rust iron III oxide or ferric oxide (Fe2O3 (hematite ore) (nonmagnetic).
rust is only a couple of the compounds of iron oxides, hydroxides, or oxy-hydroxides that you will run into with iron oxide compounds there are many more.
I am not sure what you are asking can you drop gold from an iron states, the question sounds like you have iron in solution with what you believe that you have gold in solution, first I would question whether there was actually any gold in solution, as iron is fairly high up in the reactivity series, and if you had a gold solution and used an iron rod to stir the mix the iron would be oxidized and iron would go into solution and the electron the iron gave up would precipitate the gold or plate it out onto the iron tool and would be mixed with the rust on that tool, and if by chance you did have gold in solution with an iron compound in solution you could easily cement out the gold, using iron metal or zinc metal, (copper metal would also work here, and would not drop the other metals as bad), (depending on what you are working on if iron and gold happens to be in solution together, it is also possible many other base metals are in the solution as well).
I would need more information of what we are talking about, at this point I have just been guessing what the questions are.
