Fel Iron Ore

Fel Iron Ore is mined from Fel Iron veins, with a minimum mining skill of 275.

Source
Fel Iron Deposits are found throughout Outland.

Fel Iron Deposits are by far most commonly found in Hellfire Peninsula. They are also fairly commonly found in Zangarmarsh, Terokkar Forest, and Nagrand, but do appear elsewhere.

Fel Iron Ores can also be found by fishing Heavy Supply Crate in Zangarmarsh.

Also found in Fel Iron Veins

 * (1-4) (12%)
 * (1-4) (12%)
 * (1.2%)

The following gems may also be found while mining Fel Iron Veins. Collectively, a gem appears about 3% of the time.

Smelting (Mining)

 * Smelt fel iron - requires mining skill 275
 * 2 ore are converted by into 1 Fel Iron Bar at a forge

Prospecting (Jewelcrafting)
Fel Iron Ore can be prospected by Jewelcrafters with a skill of 275, resulting in:
 * Deep Peridot
 * Golden Draenite
 * Flame Spessarite
 * Azure Moonstone
 * Blood Garnet
 * Shadow Draenite
 * Nightseye
 * Living Ruby
 * Dawnstone
 * Talasite
 * Noble Topaz
 * Star of Elune

Fel Iron Ore in quests

 * 5 Fel Iron Ore is part of the reward.
 * 5 Fel Iron Ore is part of the reward.