Updated For 5.4 Mists of Pandaria

Gem Quality

Color Popularity Gem Quality Auction Price
Red/Blue 6 star Assassin's Serpent's Eye
+160 Agility and +160 PvP Power
Epic
Red/Blue 6 star Purified Shadow Spinel
+25 Intellect and +25 Spirit
Epic
Red/Yellow/Blue 6 star Void Sphere
+4 Resist All
Epic
Red/Blue 6 star Shifting Shadow Spinel
+25 Agility and +37 Stamina
Epic
Red/Blue 6 star Mysterious Serpent's Eye
+160 Intellect and +160 PvP Power
Epic