How to Extract Grain-Sized Gold in Dirt? | Physics Forums
Aug 17, 2011· Density is the best test. Even gold dust sinks. We have a river locally that contains some placer gold, and when you agitate the pan, the regular sand and dirt wash out cleanly, leaving a reddish "sand" composed of weathered garnet, which also washes out, leaving a fine dense black material, AND (if you are lucky or skillful) gold.