Coal

Coal is a dark, stony substance used for smelting steel. It is also used for gaining Thorium Brotherhood reputation.

Source
The primary source for coal is from either a trade supplies or blacksmithing supplies vendors.

Mining

 * Smelt Steel

Coal as a Quest Objective

 * - Repeatable reputation quest for Everlook, requires 4 coal.
 * - Uldaman Quest requiring 1 coal.
 * - Repeatable quest at Thorium Point requiring 1 coal
 * - Repeatable quest at Thorium Point requiring 1 coal
 * - Repeatable quest at Thorium Point requiring 1 coal