On Wednesday, May 18, the Oppenheim Blue Diamond sold for $58.2 million—the highest price ever realized for a jewel at auction. The 14.62-carat stone, which was offered during Christie’s Magnificent Jewels sale in Geneva, was once owned by Sir Philip Oppenheimer—a member of the family that controls the De Beers Mining Company. The gem exceeded its presale estimate of $38 million-$45 million.