Darksteel is a minable resource that is extremely durable and lighter than steel. It is a newer material that is almost exclusively found from veins in the Black Mountains of Parthenia.
Demonoil is a corruptive and dangerous material formed from stabilized demonblood.
Dwarven Blasting Powder is a very rare explosive material originally discovered by dwarven craftsmen of Karak Thrund in the late Third Age.
Orichalcum is a rare, naturally-occurring magical metal found in small veins.
Residuum is an extremely rare material, created from the interaction of divine energies and the Material Plane.