Selling your "blacksand loaded with gold" will be just as much of a pain as getting it out yourself, the money you need is right there in your blacksands, there's equipment out there that will do most of the separating for you, or just man-up and pan it out and feed your family.
Maybe you can find someone local that will do the separating for you for a split of the gold, if I was in your area I would do it, check around, the time and money you will spend on selling and mailing it as gold cons will be about the same as getting someone to help with the process and doing a split.
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