In 1872, a pair of prospectors named Philip Arnold and John Slack walked into a bank in San Francisco with a bag full of diamonds and rubies and other gems they had found at a site that they refused to divulge.
They were, of course, crooks, and the gems were industrial-grade stuff they had picked somewhere.
Nonetheless, they conned a pack of investors into setting up a $10 million syndicate in what became known as the Great Diamond Hoax.
