Before we embark on quantifying your gold panning results, I might add that the key to success in your prospecting endeavours is to **SAMPLE! SAMPLE! SAMPLE! **When digging your sample buckets you need to take a sample pan after each bucket to ascertain whether or not you are still on the gold!

Quantitatively assessing your panning results is the best way to measure your exploration success. It will also be the foundation for evaluating your options for eventual mining operations. This is because a satisfactory quantitative assessment will provide two key characteristics of your discovery – grade and volume. We will focus on assessing the amount of gold recovered in a pan from your placer prospecting.

Grade is the amount of gold or (in troy ounces) in a specified volume of material. The most common measure of placer deposit volume is the cubic yard. A cubic yard contains 27 cubic feet (a 3’x3’x3’ block of sand and gravel for example).

Gold pans can vary in size so you can check on the volume of yours by using it to fill a 5-gallon bucket. A 5-gallon bucket contains 0.67 cubic feet in volume. Count how many level pans (filled without screening) it takes to fill the bucket. Divide this number into 0.67 cubic feet to determine the volume in cubic feet held by your pan. This will be a small volume. The first thing this calculation should bring home to you is that the sample provided by one pan is so small that it cannot be representative of a large amount of gold-bearing material in a placer deposit. It will take many pans from many parts of your deposit to satisfactorily sample it.

If you find that your deposit warrants lots of sampling, consider using other approaches. For one you could use 5-gallon buckets of gold-bearing material as starting samples (these buckets contain about 1/40 of a cubic yard). You can pan this material down or run it through a high-banker and pan the heavy mineral concentrate they collect from one or more buckets of material.

**1 cubic yard equals approximately 40 5-gallon buckets.**

But how do you estimate how much gold is in your pan whether it is from one pan or from several cubic feet of material run through a high-banker? Estimating the amount of gold in your pan starts with evaluating the sizes of the individual gold particles you have recovered. The four common subdivisions of gold particle size are:

**Coarse** – particles greater than 0.0787 inch (2 millimeters) across.

**Medium** – particles smaller than coarse but greater than 0.0331 inches (0.841 millimeters) across.

**Fine** – particles smaller than fine but greater than 0.0165 inches (0.4 millimeters) across.

**Flour** – particles smaller than 0.0165 inches (0.4 millimeters) across.

Coarse gold particles can be easily collected from the pan and weighed. The weight of the smaller gold particles can be estimated with the following conversions.

– 2,200 medium gold particles weigh 1 troy ounce

– 12,000 fine gold particles weigh 1 troy ounce

– 40,000 flour gold particles weigh 1 troy ounce

By counting the number of gold particles of different sizes you can qualitatively estimate the amount of gold you have recovered in the pan. For example, a pan that contains 4 medium, 10 fine, and 30 flour gold particles has 4/2,200 (0.00182) + 10/12,000 (0.00083) + 30/40,000 (0.00075) or 0.0034 troy ounces of gold. If your original sample size was a 5-gallon bucket (0.67 cubic feet) then the grade of the sampled material is 0.0034 troy ounces per 0.67 cubic feet or 0.137 troy ounces per cubic yard. This is an excellent gold grade for a placer deposit and your exploration result is very encouraging. If this grade can be shown to characterize a significant volume of material you have a discovery that warrants continued investment.

The above evaluations are based on un-classified material. If you classified material to 1/2″, your 40 buckets would be closer to 50 buckets, and if you classified to 1/4″, your 40 buckets would translate into roughly 60 buckets.