Searched: Thorium Ore Prospecting came up wth nothing relevant.
So this week I decided to level enchanting and JC on my deathknight and saw that huge emeralds were posted at 12g each. I am pretty cheap and decided there is no way in hell I am paying for that so I decided to just buy cheap thorium ore and prospect it to get the emeralds instead. I soon found out that I could make 10-20g per stack depending on how many azerothorian diamonds I earned and how many huge emeralds. So far I have made 600g in just a few days by prospecting thorium. Thought I would let the community know!
-Masolina