For the love of god though.... stop screwing with jc's and having them get stuck with craptons of 1 or 2 colors of gems that have little in the way of recipes to make use of them. (Looking at you yellows) And the crafted pvp jewelry isnt much of an improvement when you gotta blow 4 days of the jc daily tokens for 1 ring/neck. That does crap for lowering the gem stockpile.
All gems have a purpose...
Green = Jade Rings (random enchants, Rare-quality ones used to sell decently in the first half of the expansion). Also used in one of the JC Daily Quests.
Orange = Lv82 Rings (ditto, those rings were BiS until rep vendor rewards/dungeon drops)
Yellow = Lv80 Amulets (Rare-Quality were 79; these are awesome for Lv80 cap content, esp PvP).
Purple = Lv82 Amulets, also one of the JC Daily Quests.
Reds = Carnelian Spikes, an awesome Lv81 1h slow agility for hunters/shaman/combat rogues.
Blue = JC Daily Quest.
They all have their uses. The Rare-Quality gems are all used in making Perforators, the Lv83 333 1h slow agility.