There is already a post regarding running a mining route on Qual'Danas but this post, I'd like to share something I discovered about one particular node.
At 49.1, 46.9, on the Isle of Quel'Danas, there is an Adamantite node that spawns on a small ridge just behind where the Emissary of Hate spawns. This particular node, however, has a very small respawn timer. I spent about an hour yesterday grinding for Aldor rep items on the demons that spawn around it and across the course of that hour I was able to mine that one spot a total of 14 times. Additionally, a couple (I didn't keep track) of the spawns were Rich Adamantite and one was Khorium.
Anyway, g'luck.