Star Fragment are one of the GF Learning Items in Final Fantasy 8. Listed below are the effects of the Star Fragment. Where you can find the Star Fragment and how to obtain the Star Fragment.
Star Fragment - Allows the Guardian Force to learn the SumMag+20% ability - The Star Fragment can be stolen form the Iron Giant. It can alse be refined from the Iron Giant Card
More guides can be seen at the Final Fantasy 8 Forums.The complete list of all GF learning items can be found at FF8 Guardian Force Learning Items Guide. If you have more info about Star Fragment please post them below.