Darksteel

Darksteel is an alloy of iron and adamantium. It is very difficult to forge, but not as difficult as pure adamantium. It has a matte black appearance.

Darksteel is about 50% heavier than normal steel, but much stronger. So strong, in fact, that although a sword made of darksteel doesn't bend, it doesn't need to in order to resist shattering. Darksteel is harder than most metals, and many attacks on darksteel armor simply bounce off with no effect.