Diamond Hoax: Arnold and Slack's Scheme

In the midst of the California Gold Rush, cousins Philip Arnold and John Slack plotted a diamond hoax in Colorado, inspired by the 1870 South African diamond rush. They "salted" a mine to deceive investors, including a banker named William Ralston, who founded the New York Mining and Commercial Company, raising $10 million in stock. The scheme unraveled in 1872 when geologist Clarence King exposed the secret mine, leading to financial losses for investors, and Arnold and Slack disappeared with $600,000.