Sluice Concentrates

If you are using a sluice box, at the end of the day you are left with black sand (which is much heavier than the quartz and feldspar sands which are light colored) and hopefully gold in your sluice box. Every attempt is made to easily remove most of the gold next to the river, but there is always some left in the sands and so you bring them home. Thus the predicament that most prospectors are faced with is born, fine gold and black sands.

The combination of the two can be a headache, especially if all you have to work with is a pan.  When I started prospecting, I bought a spiral panning machine that separates gold or heavy materials out, called the Desert Fox.  I came very close to selling the thing, because I was under the impression that it didn't work at all. I would run all of my concentrates at different angles and water speeds and get nothing but black sand, no matter what I did. It took me a while to figure out that there wasn't actually any gold in the material I was running(duh).

Once I actually started bringing home fine gold in the concentrates, the Desert Fox really showed its true potential. I'm now a solid believer that it can separate gemstones or any denser material for that matter, and it can do so quite efficiently when set up proper. Its ease actually allows me time to do work more while I'm at the river, instead of panning out my concentrates where there is water.

My process goes something like this:

When I run material, I use my snifter bottle to pick up gold I can see on the indicator matting. This gives me a peace of mind that the gold isn't going to travel further back into the sluice, where it has a greater chance of getting washed out. Also, I have the bulk of my gold (or so I hope) to pan out at the end of the day, but its always a manageable amount of black sand. Everything else sits in the sluice until a clean-up, where I dump the whole sluice load into a dedicated concentrate bucket.

This represents two days of sluicing. The concentrates come from Cache Creek BLM area by Granite, CO

When I take this home, the first step is to classify the material through a set of screens. The screens that I use are 1/4", 12, 30, and 50 mesh. The mesh size is measured by the number of openings in a linear inch.  I dump the black sands on the screens that are set up on a bucket. I take another bucket full of water and slowly pour it through while shaking to classify it.

All of this material was removed using a magnet. Magnetite retains the magnetic orientation of when it
crystallized due to its atomic structure, and will retain its magnetism for a very long time.

Once classified, I run them in the Desert fox starting with the material between 50 and 30 mesh, and move to the coarser material. Although the machine claims to be able to separate clean gold, I haven't been able to do so without feeling like I have lost some. I always set it up so that it takes a bit of black sands too, that way I can be absolutely sure I have gotten everything I can. When the material is well classified, and with the aid of a magnet, panning the gold from the black sands is a breeze and takes only a minute or two to get clean gold.

Some processed gold from the Desert Fox

Desert Fox doing what it does best.

I'm not sure that this machine can competently separate the fine, fine gold that slips through the 50 mesh screen, so I have been saving this material in a bucket for quite some time now. Ideally, I would like to run it through the Fox and then through a Blue Bowl, because I have heard they are better for this sized material. A Blue Bowl uses spinning water that empties into a hole in the middle of a bowl to allow the fine gold to separate. I would also be willing to invest in screens in the 100, 200 and 300 range, because I'm sure that there is a lot of gold in there that is otherwise practically inseparable.

I almost didn't run my 20+ material through the Desert Fox, because I thought that it might be easier to hand pan. I'm very glad that I did, though. When I was not expecting much gold at all from this material, the big guy on the right jumped out and ran up the spiral. It is my first nugget to register on a scale, weighing in at a massive .1 grams, making its worth around $5 currently.

For two days of moving around 15-20 five gallon buckets of dirt each day, its not a very good paycheck.
For spending two days outdoors, in the sun, and next to a creek with a huge smile the whole time, it is priceless.