from the Jimmy Sierra forum
Rich says; I own this model: MXT
Do I set he MXT to find Black Sand deposits so I am able to set up a sluice to find small placer gold?...or do i need a GMT or the DFX?
Thanks...best...Rich
Hi Rich, Your guess is correct. The GMT is the only detector which will measure the "amount" of black sand in an area and thus where the gold is likely to be concentrated. The GMT also measures the type or degree of mineralization ( the number which indicates ground balance) A detector actually balances to the type of ground. Thus the value, say around 77 on a GMT would be where ferrite or pure black sand would ground balance. No matter if there was an ounce of black sand or a pound of sand it would balance in the same place. Of course if there was too much to handle that is "overload" the detector NO balance would take place. but if you lowered sensitivity or lifted the coil away from the overload amount, the detector would balance with the same number. The DFX can show you a number and so does the MXT. However it is "concentration" of black sand that would indicate a good place to sluice or drywash and that can only be done with the GMT. Good luck,
Jimmy
Me, I've learned to read the river, it looks a lot different in the winter,
I look for something to push the gold to one side of the river or the other then sample, sample sample...
using a metal detector; I'd say get some black sand and test it out with a line of it in your yard.
I think Clay has lived in the desert so long he's become hydrophobic...