Celestial Stave



The Celestial Stave is Mage-only staff that gives a bonus to intellect and magical power.

Source
The Celestial Stave was a quest reward from the Mage quest (the last stage of the  chain) which started with Tabetha in Dustwallow Marsh. It was available as early as level 35 (the minimal level required for this quest chain) however the quest chain was removed on patch 4.0.3 and the staff is no longer available.