If you find allot of black sands and the areas know for gold I would keep the sands and roast them very hot over a camp stove keep stirring them and after about 10 minutes and they get hot fracture the gold loose. Dump the sands in a bucket of ice water and if they contain gold ( usually ) fine powder's. you can then take the sand and fractured gold and run it all on a float table. Check out the 49's web site I believe I downloaded a float table plan from there when I joined. It works great you get allot of fines and powder's from black sands. Hope this helps...