Dark Days of Greyhawk
The Anvil of the Lortmil Mountains
This blacksmith’s tool was enchanted in a shrine of Moradin, king of the dwarven gods. It allows a dwarven weaponsmith to create extremely strong and sharp blades. Each weapon takes twice as long to create, but when finished is either a normal weapon (on an unsuccessful proficiency check) or a weapon of fine quality (on a successful proficiency check). All weapons of fine quality created by this anvil are worth 100 times the cost of a normal weapon of the same type. It is rumored that this anvil was used to forge legendary magical weapons for the dwarves.
The Anvil is currently held by Haethius of Gallow’s Corner in his vault.