There are currently 9 weapons that can hold "Sha-touched gems" (I know they are not really called that, but it's easier to explain it this way)(Link to the 9 weapons in the WoWhead one, below (See the comment section)). For the 9 weapons, there are 3 Sha-touched gems available, each one has either 500 intellect, strength or agility. 'Crystallized Terror' (Strength) and 'Crystallized Dread' (Agility) are the only ones that are shown in the Armoury (When looking at all gems).
Following the links to the quest on WoWhead, we can see all 3. Only 1 Sha-touched gem can be obtained, as it is not a repeatable quest:
General Facts (Taken from 'Devilsportuguese'/MMO-Champion)
"To go along with the new The Black Prince faction there are some quests that end with the reward of a legendary item, the Breath of the Black Prince! This item is likely used to upgrade your gear in some way. Before helping Wrathion, you first share a drink with him while talking about the future of Azeroth.
The first quest in the series requires an honored reputation level, which is earned by killing the mogu and mantid in the Townlong Steppes and the Dread Wastes, as well as any raid creatures.
You must also collect Sigil of Wisdom (http://mop.wowhead.com/item=87209/sigil-of-wisdom) x 10 and Sigil of Power (http://mop.wowhead.com/item=87208) x 10 from Mogu'shan Vaults, Heart of Fear, or Terrace of Endless Spring. While you are raiding, you need to defeat the Sha of Fear in Terrace of Endless Spring to obtain a Chimera of Fear.
At some point after this he will reward you with a Breath of the Black Prince, but the quests are not chained yet, so we can't be certain as to what the requirements are."
There has been no confirmation (That I know of) on whether there will be a Stamina gem for tanks, but it seems unlikely.
Currently, these 3 gems have the highest base stat increase of all other MoP gems.
Hope this helped! And sorry for any possible spoilers!