James J. Hill Sapphire
It was originally part of a necklace including 36 other sapphires and diamonds which Hill bought on December 24, 1886, and gave to his wife Mary, probably as a Christmas present. After Hill's death, the component gems of the necklace were divided among his daughters. In 2005, a descendant of Hill bequeathed the sapphire to the Minnesota Historical Society, one of the organization's most valuable donations.
In 2007, the Society put the gem to auction through Christie's to raise funds for an endowment to preserve the James J. Hill House, originally expecting to see it sold for less than $100,000. Christie's estimated an increased $250,000 to $350,000. However, the final, anonymous bid for the gem was a shocking $3,064,000, the highest price ever paid for any sapphire. The revenues from the auction provided more than half of the endowment the Historical Society sought for the upkeep of Hill's mansion.