Impure Elementium Ore

Impure Elementium Ore is looted from Elementium Slats. It also drops from the following mobs in Highmountain:
 * Uzgarogg the Seer
 * Gazarogg the Stonespeaker
 * Twilight Shardkeeper
 * Twilight Orelifter
 * Bound Elemental

As a quest objective

 * Weapons of Deathwing