Proper Assaying of Placer Samples
November 2012 by Jim HalloranThe whole purpose of sampling mineralized ground is to measure the values in a small volume of material that would be representative of a much larger volume of similar material. The key word is representative. Chemical and fire assaying will not accurately represent placer deposits by themselves.
While recovery rates are important, they must necessarily be secondary to the volume of material processed. Running more material at lower recovery rates is generally preferable to increasing the efficiency of the system.
Winters are a great time to explore the hills in the area of the Middle Camp, Oro Fino and La Cholla placers on the southern flank of the Dome Rock Mountains.
I believe dry washing is an underappreciated prospecting method. There are plenty of places where there is some pretty decent gold to be had, but the spot is a long way from any water and dry processing may well be the best way to go.
Mike and I each selected a side of the creek and started to work our way upstream. We both worked the water and sides of the creek, and better than half the gold found in this area is in the water.
Even with my favorite top-of-the-line gold detector there were several false digs. Many of the hot rocks gave a solid signal that was too much like a nugget to ignore. After trying several tests I just dug everything because it is better to be safe than leave a big, deep nugget for a more diligent gold hunter.
This past summer, a two-week adventure in Alaska and other gold prospecting trips turned out to be some of my greatest life experiences.
The more experienced prospectors know these lesser known spots are the types of places where big finds are still made.
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