One of six Infinity Gems that grant its user control over reality. According to the most commonly accepted origin story the six gems were once part of an all-powerful being who committed suicide out of lonliness. Its power survived and manifested as six gems.
The blue mind gem gives the owner psionic powers like telepathy and telekinesis or can augment the preexisting mental powers of its user. When used in conjuction with the other gems it can link its user with all other minds in the universe at once.
When the Illuminati attempted to use the Infinity Gauntlet to push away another universe that was colliding with Earth-616, the Mind Gem shattered.
X-Men Blackbird, formerly X-Men Stratojet, Professor Xavier's Rolls Royce, Sentinel Air Transport