Gloves of Spell Mastery

Source
This item is crafted with Tailoring (300); taught by Pattern: Gloves of Spell Mastery, a world drop.

Warcraft III
Gloves of Spell Mastery have a highly magical nature.

They can be found in Jaina's inventory, when she joins Rexxar in search of the culprit of the human incursion in Durotar.

In the RPG
Jaina Proudmoore wore Gloves of Spell Mastery during the time her father, Daelin Proudmoore attempted to destroy the horde that had settled in Kalimdor. These thin leather gloves look like any other set of leather gauntlets until worn by an arcane spellcaster. In such a case, they begin to shimmer and glow with a striking array of colors that constantly shift and change through all hues of the rainbow.