An online video gave me some ideas, and with a lot of trial and error I developed a reliable method of panning free gold particles down below 35 microns quickly and easily.

…as an academic argument, when mated to the appropriate engine, is the pump really moving water at the rate of 400 GPM?

Silver refining has been used from ancient times to change the characteristics of the metal. Early metallurgists refined silver by heating it a couple hundred degrees above its melting point and holding the metal at an elevated temperature for a period of time.

The first and most important thing of the sampling process is to try to be as unbiased as possible. There is a natural tendency to select rock that looks the best—even unconsciously.