I wanted to replicate the telekinesis ability that most unicorns have, so I studied various levitation technologies. The real ones aren't very impressive, so I ended up modeling the horn loosely after the (100% fictional) zero point energy field manipulator(gravity gun) from Half Life 2, which appears to hold a zen crystal. So the 'gem' is really only intended to function as some sort of catalyst for telekinesis. Her primary power source isn't illustrated.