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Impure gold, as it commonly occurs in deposits, has a density of 16 to 18, whereas the associated waste rock (gangue) has a density of about 2.5. The difference in density enables gold to be concentrated by gravity and permits the separation of gold from clay, silt, sand, and gravel by various agitating and collecting devices such as the gold pan, rocker, and sluicebox.

Mercury (quicksilver) has a chemical affinity for gold. When mercury is added to gold-bearing material, the two metals form an amalgam. Mercury is later separated from amalgam by retorting. Extraction of gold and other precious metals from their ores by treatment with mercury is called amalgamation. Gold dissolves in aqua regia, a mixture of hydrochloric and nitric acids, and in sodium or potassium cyanide. The latter solvent is the basis for the cyanide process that is used to recover gold from low-grade ore.

YOU CAN STRIP THE GOLD BY REVERSE PLATING i.e., MAKING THE JOB AS ANODE IN AN ELECTROLYTIC SOLUTION OF 90%NaCN , 15%NaOH AND 15% SODIUM META NITRO BENZENE SULPHONATE, AND STAINLESS STEEL AS CATHODE. GOLD WILL DEPOSIT ON CATHODE. JUST PEEL OFF THE GOLD AND REFINE IN ACID MIXTURE OF NITRIC OR SULPHURIC ACIDS, OR DISSOLVE IT AQUA REGIA, DILUTE THEN ADD SODIUM META BISULPHITE, PURE GOLD WILL PRECIPITATE AT THE BOTTOM.