How Two Miners Fooled San Francisco’s Richest Men

In 1872, two cousins from Kentucky convinced some of the richest and smartest men in San Francisco that they had found the biggest diamond field in America. Philip Arnold and John Slack showed up with a leather bag full of rough diamonds, rubies, and sapphires. Then they took investors out into the high desert near the Colorado–Wyoming border and let them “discover” gems scattered everywhere. There was just one problem. Arnold and Slack had planted them. This is the story of the Great Diamond Hoax of 1872—how two prospectors fooled William Chapman Ralston of the Bank of California, mining engineer Henry Janin, Charles Tiffany of Tiffany & Co., and investors who raised around $2 million for a diamond field that never existed. Then a young government geologist named Clarence King rode out to the field, looked past the sparkle, and found the one thing nobody else had noticed: diamonds, rubies, and even a cut gem sitting in the top layer of dirt. The stones were real. The diamond field was not. This is one of the wildest scams in California and Western history.