Specifications unknown, legend tells that the ring can "grant infinite wishes". It remained hidden as the Liberl Ark's power core, which levitates the floating city and functions as the city's master computer, fending off all that harm it with its judgmental self-defense mechanism.
It was briefly mentioned in FC's Final Chapter by Alan Richard, as part of his final plan. But in Trails in the Sky SC, it fell into Georg Weissmann's hands all according to his manipulation of events of resurrecting the floating city. Upon his acquistion, he eventually absorbed the treasure turning him into the game's final boss.