When two men appeared at the Bank of California with a bag full of diamonds, they caused a stir. The year was 1871. The prospectors with the diamonds were Philip Arnold and John Slack. The duo claimed to have found a diamond field at an undisclosed location in the West. Investors were eager to capitalize on the find.
Arnold and Slack gave up the rights to their discovery, pocketing about $700,000 between them. Meanwhile, a corporation was formed to excavate the diamond field. Speculation was that the diamonds were found in the northwestern corner of the Colorado Territory.
Some U.S. geological surveyors heard about the discovery in 1872. They assembled a small team and soon they discovered diamonds, but in suspicious locations. One diamond had clearly been worked on by a lapidary tool. The jig was up. The supposed diamond field had been salted with coarse diamonds purchased in Europe. The wealthy investors had been duped.
Learn more in the Lowell S. Hilpert papers at UW’s American Heritage Center.