Cardinal Ruby

Cardinal Ruby is said to be the finest gem in all of Northrend. As such, it is usually the most expensive gem across the player economy. It is the Wrath of the Lich King equivalent of Crimson Spinel from The Burning Crusade.

Source
This item can be obtained via the following means:
 * Jewelcrafters of level 450 may prospect Titanium Ore for a chance to get a Cardinal Ruby.
 * Alchemists of level 450 may Transmute to obtain Cardinal Rubies - Transmute: Cardinal Ruby. Recipe is a reward from the quest Cardinal Ruby (quest).
 * Jewelcrafters of level 425 may also create Icy Prism, which has a chance of yielding an epic gem.

Jewelcrafting

 * Bold Cardinal Ruby - 10 Strength
 * Brilliant Cardinal Ruby - 10 Intellect
 * Delicate Cardinal Ruby - 10 Agility
 * Flashing Cardinal Ruby - 20 Parry
 * Precise Cardinal Ruby - 20 Haste

Tailoring

 * Bejeweled Wizard's Bracers
 * Bejeweled Wizard's Bracers