This guide will list the places where I found the most [Volatile Earth]. One thing I noticed while farming Volatile Earth is that sometimes you farm for 15 minutes and you don't get a single Volatile, this is just bad luck, don't get discouraged.
Zul'Gurub - dungeon
Zul'Gurub is a level 85 heroic dungeon, so you should be able to solo this instance at around level 90. Scroll down to the bottom of the page to find alternative farming methods if you don't have a high level character.
The entrance to this dungeon can be found in Northern Stranglethorn at the coordinates 72 33. (picture of the exact location)
/way Northern Stranglethorn 72 33
First, you have to set the instance difficulty to Heroic (right click your portrait). This dungeon doesn't have a Normal mode, so you can't enter until you set the difficulty to Heroic.
There are two elites mini-bosses in Zul'gurub that you can kill and drop volatiles every time:
- Tor-Tun drops 5-8 x [Volatile Earth].
- Florawing Hive Queen drops [Hive Queen's Honeycomb], which contains 4-6 x [Volatile Life] and 4-6 x [Volatile Air].
Don't kill any other bosses or you can't reset the instance!
After you killed one of these bosses, or both of them, you can go outside and reset the instance by right clicking over your own portrait then click the "Reset all instance" button. This restarts the whole instance and all mobs will be back. You can only do 10 instance runs in an hour, so you will have to wait a bit since one runs usually won't take longer than 2 minutes and you will hit the instance cap in like 20 minutes.
You can farm Volatile Earth in Twilight Highlands by killing Obsidian Stoneslaves. Do not forget that if you are a miner, you can mine the dead mobs and you will get more Volatile Earth.
There is another good place is in Mount Hyjal. Kill Scalding Rock Elementals. These mobs are easy to kill and the respawn rate is pretty fast.
Contact me if you have other great farming spots!