Nulltrium Ingot

Trade Good

Very Rare

An unexpectedly heavy, violet metal, Nulltrium truly is the bane of all magic users, capable of nullifying mid-level spells by its presence alone.
Nulltrium is primarily found in the continent south of Drucin, and as such is very hard to come by. In fact, most commoners and ever most royalty have no notion of its existence. When it appeared is still under debate, some say it appeared at the same time as mana steel, others say it is as old as the world itself.
— The Truth of the Third Age by Siroc Relvish.

TL:DR

Anti-magic metal, Very Rare.

Weighs about as much as tungston. Stronger than steel, but not by much.

Weapons deal double damage to spellcasters.

Weapons have advantage to hit creatures within (reach or 1/2 range) that are concentrating on a spell.

Gives Magic Resistance to armor.

Cost: 1 GP