@Richard.Hein: So really you posted to point out that I used an absolute term. Yes, I shouldn't have used an absolute term. I should have said "nearly impossible". Congratulations. You win.
* that. I take that back. My statement of impossibility is based on whether or not gold is non-reactive. Given that, how do you separate any type of non-reactive particulate from another using a chemical reaction? Non-reactive elements by definition cannot chemically react. So the statement of impossibility is true under those circumstances.
So the main issue in that statement is whether or not gold is non-reactive, and I've stated several times already, gold is reactive under certain conditions but effectively non-reactive under the conditions that can exist inside of a living coral specimen.
Another thing you can argue is whether or not coral has to use a chemical process in the first place as evildictaitor questioned, and I've already stated several times that a mechanical process would require the development of specialized organs.
EDIT: nvm, idc.