Ken Rutherford is a well-known name in the precious metals business. He makes and sells the Fisch instrument, a simple but effective tool that tests coins (by seeing whether they fit through calibrated go/no go slots and by a balance test).
He is also the author of a guide to counterfeits published over 25 years ago and revised several times. Here is what he said back in 1984:
The silver and gold business is crazy. Investors send $10,000, $20,000, even $40,000 to firms they’ve never even heard of and whose credit they’ve never checked. They just close their eyes, lick and send the envelopes and send their checks winging away.
Times change. Since Rutherford wrote that, gold scams have migrated to the Internet, and today people click their money away to unknown URLs; or, in a similar but also risky scenario, send their gold (coins, bullion, jewelry or scrap) to some address, from which they hope somebody will send them cash.
Rutherford recommended dealing only with established dealers. That’s still good advice.
He also recommends, when buying gold coins, to TEST EVERY ONE. Still good advice. But hard to do over the Internet.