If gold isn't in a standard form like a Krugerand or Maple Leaf or in a bar that has been assayed and has a serial number of it from a known source, no reputable place will buy it, except maybe a place that will melt and assay it for you for a fee, and they'll probably ask questions, like, what is the source.
A old client of mine is a major metals dealer. One of their trader's got a call from Bolivia.I have lots of melted gold, how much will you pay me for it. The trader listened then said, Look, you stole the gold, We don't want it. We only buy known assayed reputable gold.