What is it that you need to do to be successful as a prospector and how do you identify a deposit with profitable quantities of gold? Unless you are in it for the fun and getting lots of exercise, these are important questions.
The first and most important thing is to find a large quantity of gold-bearing material that has enough recoverable gold to add up into a measurable quantity. Once you have found a suitable deposit, you must procure a method of processing the material fast enough so that the gold recovered will cover your expenses.
Rich gravel is likely found in small deposits, and low grade deposits are more likely to contain considerable volume. The only way to make money from an area with very little workable material is if the gravel that is there is extremely rich, which usually isn’t the case, as the rich areas were worked a long time ago. Instead, focus on low to moderate grade areas with an abundance of gravel and the gold will add up, sometimes surprisingly so.
One area to look for are places with two to four feet of gold-bearing gravel on top of bedrock. This material does not need to be rich, and tends to have predominantly flour gold with the occasional small nugget. Sample around until you can locate a place with three or four small granules or 20-30 specks of flour gold or more per sample pan. A few pieces of gold per shovel along with a smattering of flour gold add up fast when you are running 50 to 100 shovels of material through a high-banker on each run.
In addition to having a deposit large enough to be worth mining, you also need to process the material fast enough to get the gold in a reasonable time frame. It’s the volume of processed material that is the key to success. The more material you can work in a given time, the lower the gold grade in the material that can be worked economically (and the more gold you can recover). 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.
As an example, let’s say you have gravel that has a placer value of $25/yard, and you can run one yard of material per hour at 90% recovery: $25/yd. x 90% x 1 yd./hour = $22.50/hour. If you run the same gravel faster, doubling the production rate, you will likely lose some recovery. Let’s say recovery drops from 90% down to 70%: 2 yards x $25/yd. x 70% x 1 yd./hour = $35/ hour.
By doubling the volume, you have just increased your profit margin by 64%, even after losing approximately 20% additional recovery. More volume almost always means more gold. The trick, however, is to find out where the correct balance point is between efficiency and volume.
One of the most common places prospectors face this dilemma is on the bank of a river with a gold pan. Most will spend 5-10 minutes to work down a pan of gravel—they are always careful not to lose any gold. What if you pan down a similar pan of gravel in 20-30 seconds, with water splashing recklessly everywhere. How much gold would you lose? If you recover 95-100% of the gold, but only work one pan in five minutes, you would recover about seven to eight times as much gold in the same amount of time, even with a 25% loss.
When working with concentrates, such as that from the high-banker, you will definitely want to slow down and pan into a second catch pan. Once the grades go up, production must necessarily slow down to some extent.
Graduating from the basic gold pan to some other form of simple equipment is the best way to increase production rates. Just going from a pan to a high-banker will increase production by 500% to 1000%, depending on how it is used. A high-banker will move the water to you—instead of you bringing the gravel to the water—thereby dramatically increasing volume of production. It is important to note that a high-banker is a production piece of equipment. It will not find you gold. This is where proper sampling is crucial. I have seen too many times where prospector’s blindly shovel into a high-banker randomly only to find there is no gold in the box after shovelling all day.
Finding a suitable deposit to mine and finding a way to work it economically—something that will justify the time and expense of setting it up—are two of the most basic skills. Fun and exercise are good reasons to go prospecting, but you might as well make some money while you are at it.