Bring 10 Linen and the 6 Charged Rift Gems to Wynne Larson in Stormwind.
You have served your fellow mages well, and now it is time to don your wizard's robe. Wynne Larson can make your robe, but you must bring her the needed materials
The robe will be made of linen which is easy to find, but you must also gain charged rift gems, and the only known location of the gems is in the Silver Stream Mine of Loch Modan, left in crates by the dwarven miners' league.
Gather the linen and the gems and bring them to Wynne Larson at the Larson Clothiers in the Mage District.