Montana's Yugo sapphires are a little known American treasure. The cornflower blue stones are only found in remote portions of Montana and are prized for their deep color. Jewelry pieces made using these stones will be auctioned off to benefit Montana's Special Olympics program in an upcoming event. The pieces include a bolo tie worn by Montana's Governor Brian Schweitzer as well as a variety of sapphire and diamond rings, diamond earrings and diamond pendants. An online auction has already begun and the highest online bid will be the opening bid on items at a live auction as part of the Montana Sports Legends Dinner and Auction on October 3. The auction item shown above includes a trillion cut Yogo sapphire that is over one carat along with matching earrings featuring sapphires and diamonds set in yellow and white gold. The lot has a total value of $24,000. Online bidding ends September 30.