In 1871, cousins Philip Arnold (1829-1878) and John Stack (1820-1896) perpetrated what became known as the Diamond Hoax of 1872: they claimed they had discovered a diamond mine (in northwest Colorado). They bought industrial grade diamonds (used for drill bits) and took them to some businessmen. They received a $50,000 down payment to buy their claim (equal to about $980,000 in 2018). They spent $20,000 to buy more gems in order to "salt" their claim; Tiffany & Company jewelry appraisers valued the stones at $150,000. The cousins were paid $660,000 for their claim (nearly $13 million in 2018). Afterwards, Arnold returned to Kentucky and started a bank; Slack moved to New Mexico and became an undertaker.
