From time to time you tilt the pan with your extended thumb to push off the surface layer and continue shaking. An experienced panner can pan about a cubic yard of gravel a day. Place a magnet inside a plastic film container and roll it around in the black sand. Then give the container a good shake and all of the magnetite will fall away from the container. When working gold placer deposits in a river or stream, prospectors use gas powered siphons to dredge the sand and gravel in the crack and pockets of the bedrock on the bottom of the waterway.
Prospectors then run the material through a sluice box to catch the gold.
Sounds simple, but someone has to dive down and operate the siphon hose. These gold concentrations are called placers. In a dry wash, you must dig down in the gravel until you hit bedrock. Well, that's about all you need to know, except that virtually all of the land in Llano county is privately owned. You must get permission from the property owner before panning.