The crystal fundamentally alters the properties of matter - it causes matter to loose inherit mass on a subatomic level. This causes the matter to retain its shape but alter its density, hardness, malleability, while it is in use. Energy can be drawn off of an object altering its mass in a more lasting way, but this process is never destructive, while the crystal is in use matter is altered but it returns to its natural state once the crystal is no longer being used on it. Even if energy is drawn off, the matter will always eventually regain the energy and be restored to its natural state.
This crystal bonds to its wearer within seconds of being held. Once bonded the person beings to innately realize how to use its abilities. The bonding process cannot be reversed by any known means, even after a person dies it is likely (though untested) that the crystal can no longer be bonded to anyone else. Some time after bonding the wearer begins to get precognition abilities, able to sense oncoming events which have a large amount of emotional impact. The time into the future to which the person is able to sense, depends on the severity of the upcoming emotional impact - but is never more than a few moments in time.