Hellstone

 Hellstone is a material and its products are the highest tier items currently available in the game. It is only found in the deepest layer of the world, The Underworld. Mining Hellstone now requires at least a Nightmare Pickaxe. It can be smelted into Hellstone Bars only at a Hellforge, and as of 1.0.6 requires only 4 Hellstone and only 1 Obsidian. Like most other ores and soils, it can also be crafted into a Hellstone Brick at any furnace. As of update 1.0.6, hellstone, when broken in the underworld, will spill lava into the surrounding area. A great counter to this is Obsidian Skin Potion. Hellstone deals 30 (without armor) fire damage to the player when they touch it, unless they wear an Obsidian Skull or use an Obsidian Skin Potion. If the player made a Hellevator, the player would not take damage,(Granted they don't have the Lucky HorseShoe.)

Mining Tips
Mining Hellstone can be a significant problem, not only because Hellstone deals fire damage to the player (which can be negated with an Obsidian Skull); but mainly because of the dangerous monsters of The Underworld. While Bone Serpents appear, they can be a problem and should be fought like one would fight any worm monster, preferably using very long range weapons such as the Vilethorn. The greater threat are the Fire Imps because they constantly respawn and their fireballs can penetrate walls. When killing Underworld monsters, it is best to obtain a higher teir of armor and good equipment to mine and attack.

Note: When the Player kills an imp, there is a respawn time, meaning that they won't spawn right after you kill them. So if you see them in a hall way right beside you, run up to them and kill them with whatever weapon and they won't bother you after a little bit.

One approach to mining Hellstone can be to just drop down to the Hellstone / Ash "floor" and start digging out the Hellstone. Since all Pickaxes are pretty fast and swing continously, this should deflect most fireballs and kill most Imps that stand in front of the player. One should take care of the Imps spawning above them by mining as narrowly as possible and preferably straight downwards. With decent armor, an Obsidian Skull and one or more Bands of Regeneration, a player should be able to mine a decent amount of Hellstone before he is killed by the Imps or a Bone Serpent. One must keep in mind, however, that Hellstone Bars are very expensive and difficult to aquire as 6 pieces of Hellstone and 2 pieces of Obsidian are required to forge only one bar.

Additionally, as long as a player leaves a roof of 3 blocks high (minimum moving space), imps rarely teleport into range of you. In other words, try not to leave any space with a roof higher than 3. It also helps to work deep enough to be under the forge chambers.

Note: It is extremely helpful to use the Obsidian Skin Potion in conjunction with the Gills Potion, as it not only grants the user immunity to lava, but also allows them to breathe in it.



Update info
1.0.6 - Hellstone now creates firey sparks, but they don't do damage. Hellstone also spawns lava when it is mined, but only in the underworld. 