Hellforge

The Hellforge is a Furnace that can only be obtained from Underworld Houses. The Hellforge acts as a normal Furnace except it can smelt Hellstone and Obsidian into Hellstone Bars. Hellforges can be collected by using any Hammer tool at the Meteor tier and higher or by destroying the ground it is placed on. The Hellforge can be used to replace the Furnace entirely as it can smelt all the same items.

Trivia

 * The Hellforge is possibly a reference to Diablo II in which the player must travel to the depths of Hell in order to destroy Mephisto's soulstone using the Hellforge.

Bugs

 * In the console version of Terraria, hellforges DON'T spawn anywhere in the underworld, but anywhere above.