Originally Posted by
Socronoss
You get all 1-star recipes through quests at 100, 102, 104, 106, 108 and 110. Last one gives you an additional vendor in the Dalaran Jewelcrafting shop that sells all remaining 1-star recipes.
2-star recipes can also mostly be bought in the same shop. 2 of them come from the sewers (PvP currency required) and some (2 i think also) from dungeon drops.
3-star recipes come from either Reputation-gated vendors, dungeon drops, 1 you can even fish up.
Getting the recipes is not the problem, getting the mats for them, though... For example: I had to prospect more than 2,000 leystone ore and more than 1,500 felslate to get the 4 large yellow gems to make the priest neck (ilvl 815, upgradable). JC has become THE go-to profession for masochists who love being at the complete mercy of RnG through prospecting.
6 gems, small and large, that's 12 possible outcomes and around 30% of all prospects (5-ore) give you nothing at all (you can vendor the shards you get). If you really want to specifically get one, you might enjoy having to farm ore for several hours straight just to find out at the end of it: You didn't get the color you want at all.
No transumtes of colors either!