Hellstone

Hellstone and its products are the highest tier items currently available in the game and is only found in the deepest layer of the world, The Underworld. Mining Hellstone requires a Nightmare Pickaxe or better. It can be smelted into Hellstone Bars at a Hellforge, which requires 4 Hellstone and 1 Obsidian. As with most other ores and soils, it can also be crafted into a Hellstone Brick at any furnace.

Hellstone deals 20 fire damage to the player when they touch it, unless they wear an Obsidian Skull or drink an Obsidian Skin Potion. It also releases half a block of lava when mined in the Underworld, making it a very dangerous material to mine.

Hellstone is invulnerable to all forms of explosives including Dynamite blasts.

Mining Tips

 * See also: Guide:Mining Techniques.

Mining Hellstone can be a significant problem, not only because Hellstone deals fire damage to the player (which can be nullified by equipping an Obsidian Skull); but mainly because of the dangerous monsters of The Underworld. While Bone Serpents don't appear very often, they can be a problem and should be fought like one would fight any worm monster, preferably using very long range weapons like the Demon Scythe or area affect weapons like the Grenade. The greater threat are the Fire Imps, because they constantly respawn and their fireballs can penetrate walls.

Using sand
Hellstone drops lava when mined. An effective way to get around this is by using sand's falling property. Place a sand block over the Hellstone, mine the Hellstone, and the sand will fall onto the produced lava, removing it.

Using potions
Using an Obsidian Skin Potion and Gills Potion together will allow you to mine in the lava itself. This can keep you safe from many of the spawns (Fire Imps and Bone Serpents being notable exceptions).

Using an Artificial Meteor Biome
If the Player places at least 50 pieces of Meteorite Ore on the screen where they are mining, they can create an artificial Meteor Biome. In the Meteor biome, all monster spawns are replaced by Meteor Heads, which are more predictable, and tend to do less damage, than the naturally spawning creatures of The Underworld. If the Player can withstand the Meteor Head attacks he can mine Hellstone in relative peace.

If this method is used, the Player only needs to take care to move his Meteorite deposit as they mine away from it. Refer to the Meteorite page for tips on safely mining in the Meteor biome.