Blizzard released a new page for the official Burning Crusade site showcasing the Jewelcrafting profession. Not only can you mine minerals to acquire gems, the expansion bosses will drop them. It’s worth checking out:
Jewelcrafters work with gems in many different ways. If a jewelcrafter uses gems to create jewelry, he usually only needs the raw, uncut stones for his work. These rings, amulets, and trinkets function just like those that can already be found in the game, with a few notable exceptions. For example, jewelcrafters can learn to create gemmed figurines that they can carry in their trinket slots. While these figurines all provide passive benefits, they can also be used to provide the player with a short buff ? just enough to give you that little damage boost or maybe that quick burst of extra healing power you may need in a tricky situation. These figurines will bind when picked up, so only jewelcrafters will be able to use their powers.