Mithril ore

Mithril ores can be found in the Dwarven mines and in the Lumbridge swamp. They require level 55 Mining to be mined. They grant 542 experience per ore.

A Mithril ore can be smelted to a Mithril bar in a Furnace, using 1 Mithril ore and 2 Coal. You can also use Superheat Item on a Mithril ore to get a Mithril bar, but you still need to have atleast 2 Coal in your inventory.

Mithril bars are further refined in the Smithing skill.