Sifting gold bearing material is referred to as "Classification". Classification is an essential step in the most efficient recovery of gold. It is very important to try to filter out any unnecessary material prior to using your gold processing equipment of choice to recover gold. Using a classifier, paydirt is sorted using specific gravity. Gold weighs a lot more than the granite and other stones that often fill your bucket. By classifying material into an equivalent size, you will maximize the effectiveness of the equipment used to process the material.
Gold classifiers come in many different sizes or “mesh”. These meshes are usually measured in fractions of an inch. Meshes smaller than one eighth of an inch are often referred to differently. For example, mesh that blocks material larger than one twentieth of an inch is referred to as “twenty mesh”, mesh that blocks material larger than one fiftieth of an inch is called 50 mesh, etc. High Plains Prospectors stocks gold classifiers in sizes from one half inch to 100 mesh. You can nest several classifiers together and get through material more quickly than classifying down one step at a time.
Classifiers for gold prospecting and gem hunting come in several shapes and sizes to help classify paydirt into a size that is easier to process. Our most popular classifiers are 14” across and fit on top of a five-gallon bucket. This allows one person to shovel paydirt onto the classifier and the other person to shake it down to size. The classifier allows the smaller paydirt to fall into the bucket for further processing while blocking the larger material that could clog fine gold recovery tools. When using a classifier, be sure to always check the material before discarding so you don’t throw out any monster nuggets or huge gems! Two people can fill several five-gallon buckets with classified paydirt in a brief period of time which means you can move more dirt and find more gold or gems.
It's good to know the size of the gold in your area when you’re trying to decide on the right size classifier for the material you’re going to process. If there are nuggets up to a half inch in diameter in the area, you’d want to start with a half inch classifier. Be sure to look through the material left behind before discarding it or you may throw away a fortune. If most of the gold recovered in the area is known to be small flakes or flour gold, you’ll want to classify the material down a lot finer before sending it through your plant. Be sure to test-pan your material to see what size gold you’re generally working with. Classifying is also a great way to catch and discard tiny roots you may dig up which would otherwise clog up your plant. Classifying your paydirt down to the smallest size possible will help gold recovery be more efficient. If you’re sending big material through the sluice, highbanker, or Gold Box but you need to catch fines, the larger material can clog up your plant and stop you from catching gold.
Gold that is larger than an eighth of an inch would be considered a “picker” because you can pick it out of the box with a pair of tweezers. When operating a small plant, like a highbanker, it’s good to classify material down to one eight inch and run that material.
Regardless of what you use to run your paydirt, whether you use a highbanker, trommel, spiral wheel or a ground sluice, an important step is to classify the material. Classifying down your material makes it easier for your plant to catch the gold you’re hunting.