Panning for gold involves shaking gold-bearing dirt and water inside a shallow pan to help the gold to sink and the water and dirt to be swept away. Because gold is a heavy material, it sinks to the bottom of the pan to be collected by the prospector.
The New 49'ers explains that panning for gold starts by placing dirt about 3/4 to the top of the pan, then removing larger rocks. It is also possible to sift the dirt through a screen at this stage to get rid of larger pieces of material. The next step is to choose a good stream-side location for panning. The best spot will have somewhere to sit, clear water and a very mild current. The pan should then be placed just underwater.
While the pan is underwater, the prospector should break up all the dirt clods, roots and moss with his fingers until all the material in the pan is fully separated. During this stage, dirt and silt float away with the current. This is nothing to worry about, since gold is heavy and sinks to the bottom of the pan.
The next step is to shake the pan gently back and forth while underwater, sweeping away rocks that float to the top of the pan. This step is typically repeated several times. Finally, the pan is tilted to allow lighter material to be washed away. When only heavy material is left, the prospector can start to pick out bits of gold in the pan.