It is a piece of the dragon; a scale - enchanted and transformed. Whole, it could have granted access to the beast's lair. Shattered, it is useless.$B$BIt is possible to repair the item, but to do so would require the blood of a black dragon champion. There is one... He is known as General Drakkisath, ruler of the dragonspawn armies of Nefarian. Perhaps you have heard of him?$B$BReturn with his blood, $r, and I shall enchant the fragment into something that will grant you access to Onyxia's lair.