I would have to search for it but there is a video on youtube of some guys that crush rock to get the gold out. And I know you can find it in quartz, but that is about all I know
So far, i'm responsible for about 80,000 smashed quartz rocks in calif. gold country - no luck on dry land yet. I did dredge up a nice gold-quartz specimen
which is shown early in the SLUICING thread "Show me your best finds"
Heavy rusty quartz specimens are good candidates for crushing. Use a rock hammer/pick and magnifier to sort. And know
what native gold looks like. If it looks nice and shiny in sunlight shade the sun to see if it looks the same in shade. Fools gold
won't shine in the shade.