Enchanted Mithril

 is an item that is used in various recipes. It is unlocked at.

Crafting
is crafted with 160 regular Mithril.

Refined Mithril
160 in the forge which is unlocked at HotM 2.

Upgrading Mithril Minion (V-X)
Also used to make a Mithril Golem Pet.

(someone please add recipe)