Gold is often found within quartz veins in gold-bearing parts of the United States and around the world. The quartz veins can be found deep underground and generally run horizontally and are anywhere from a few inches to a couple of feet thick. If you find quartz that contains gold that is substantially visible, do not remove it; it is more valuable left as is when sold to collectors. If there is less visible gold within quartz that you want to melt out, know that it is a highly toxic process and you must take precautions to protect yourself. This process can be done on a large, commercial scale or on a small scale at home.
Put on safety goggles and a respirator. A respirator (available at most hardware stores) is a face mask worn over the mouth and nose to protect you from noxious fumes and harmful particulate. Crush the quartz with a sledge hammer into pea-sized pieces.
Transfer small pieces to a mortar and grind the pieces to sand-like consistency with the pestle. This will take some time and effort to grind the pieces to the correct consistency.
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Put the sand into a gold pan and add water. Swirl the mixture in a clockwise fashion, allowing the water and other materials to slosh over the edge. Gold, having a very high specific gravity, will stay in the pan and settle in behind the ridges or “riffles.”
Put on long rubber dish gloves and start the process of cyanidation. This is where you add a very diluted mixture of cyanide and lime to the gold in the pan. This can be purchased from a company that specializes in gold recovery chemicals such as Shor International (see Resources). This solution will melt the gold, turning it into liquid form and separating it from the other materials, if any, left in the pan.
If you want to turn the gold back into a solid state, add zinc dust.