This is more about jewelcrafting from the expansion.
Prospecting is trainable at 35 jewelcrafting skill. Prospecting is used like your jewelcrafting skill, you select it from your abilities menu, and then select a stack of ore (almost like disenchanting). It takes 5 of the same type of ore to use prospecting. After clicking on the pile of ore, it removes 5 more from your backpack.
After removing the ore from your pack, a loot box opens up. You get some gems, that you can use and you get some Copper Dust (if you are using it on Copper Ore). As far as I can tell, the dust isn't used for anything and its also gray which confirms that
I have some pics about this but i dont know how to put images in![]()