Mining Engineering student here! A couple of things I'd like to toss out. I have never worked at a gold mine, but I know people who have worked in the gold mine in Kershaw SC. The Mica Schists can be a vector for gold and I am pretty sure it would have to be in a native form, but I do not know for certain (again, no experience in one of these deposits). You mention floating the gold, and while that is the way we liberate gold in an industrial setting, you have to crush it down to an extremely small size for it to work. Flotation only works when you make the target mineral/metal so hydrophobic that its attraction to air is stronger than the force of its weight which wants it to sink. Unless you use straight mercury as a collector, you'd have to have a specialized setup to float gold. You'd be better off trying to use a gravity separation method, like panning or a shaker table, if you actually have gold.