Tome of Arcane Brilliance 2

Tome of Arcane Brilliance 2 used to teach a mage the spell Arcane Brilliance (Rank 2). Learning the spell consumed the tome.

Source
This tome drops from elites in most high-level Burning Crusade dungeons, such as Tempest Keep, Shattered Halls, parts of Auchindoun, The Steamvault, Caverns of Time, Karazhan and also in heroic dungeons.