Shard of a Dead World

Source
This item is a quest reward from Mark of the Sentinax (quest). It is also a reward from Duty's End. This item also drops from the following Legion Assaults commanders:
 * Lord Commander Alexius in Stormheim
 * Dread Vizier Gra'tork in Val'sharah
 * Fel Commander Erixtol in Highmountain
 * Xeritas in Azsuna
 * Commander Vorlax in Azsuna