THX-1138

It's a residue -- essentially dust. 0.1mm wide at the largest, most much smaller. And around m0.005mm maximum thickness at a guess. Small enough to be strongly affected by Brownian motion. And actually, no, they aren't quite distinct. At 15X, which is rather stronger than a hand lens, I've manually separated most of the obvious bits -- but there are plenty of UNobvious ones. Thanks for the suggestions for alternate procedures, but I'd also like to pursue my original idea of using chemistry rather than mechanics.

I have about 2cc of 0.1mm particles (and smaller), some of which are flakes of placer gold but most of which are common mica. I want to separate these. A centrifuge would be useful -- if I had one, which I don't. The particles are small enough, as is my skill in the technique , that panning is suboptimal. So I'll try falling back on straight chemistry to remove the mica threads from among the gold. Short of HF, what would be good for dissolving the mica fragments? YT2095 says that heated solutions of some common hydroxides (NaOH, KOH, LiOH) will attack glass (and I'm extrapolating to hope they'll go after other silicates), but my first attempt -- glass in boiling NaOH solution -- yielded no discernible effect. Perhaps I didn't meet the necessary criteria, or perhaps the effect is too small to be useful in this case. DrDNA suggested aqua regia or piranha, but aside from being things I want to avoid, they won't help -- both are safely stored in glass, and aqua regia would dissolve the gold and leave the dross. So, any alternative ideas for something that will dissolve mica but leave gold and a nickel or carbon crucible untouched? (Yes, I realise I'm not talking about putting the mica into solution, but 'dissolve' gets the idea across adequately, I think. ) TIA..