Ostlerheimer Diamond

The Ostlerheimer Diamond was a jewel located in the Manehattan museum.

History
After "Rough Diamond" stole the gem, she hid it in Trixie Lulamoon's hat in order to frame her with it. Even though Trixie had tagged the gem with an iTrack chip, she was unable to realize who stole the gem. As Trixie's reputation wasn't exactly solid by this point, the Manehattan Police Department didn't exactly trust her and believed her to be the true thief. Applejack, Babs Seed, Rarity and Fluttershy all believed her when Trixie said she was innocent, but Apple Bloom took some convincing. Eventually, they managed to track down the actual thief, Officer Fluffles.

The theft of the gem was reported in the newspaper, Equestria Daily.