This item is crafted by Tailors with a skill level of 300.
The components are:
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.
They could be found in her inventory in the Warcraft III: The Frozen Throne Bonus Campaign, The Founding of Durotar part 2.