Netherstone is a stone that is found only in the The Nether.
Consistency: Hellstone is delicate. It can be mined with one hit, even using a stone pick. It can also be broken relatively easily by hand; however, using your hand or a tool other than a pick will drop no material. Hellstone has an extremely low resistance to TNT and can be destroyed by the Ghast's fireballs.
Appearance: The dark red of the stone, along with its abundance in The Nether, give it a very chilling ambiance and make the region seem darker than it is. Hellstone gives off a small amount of light estimated to be the same as the nightime lumination from the moonlight. Thus, it is never completely dark in The Nether, even on blocks far away from light sources.
Uses: As of Alpha version 1.2.0_02, there are no recipes using Hellstone. Its only use is the ability to burn forever, once lit on fire using Flint and Steel. This makes Hellstone a good source of light and allows the creation of Hellstone traps (below). If Hellstone is set on fire, the fire will not spread to flammable blocks placed above the flame. It can also be a useful way of attacking Zombie Pigmen without enraging them.
Hellstone Traps
It is possible to place several single tiles of hellstone across one's outside home area and light them on fire using flint and steel. Animals will carelessly jump on top of the blocks, catching on fire and more often than not they will jump off of the burning hellstone and drop loot in a safe location. After a while, lots of animals will kill themselves on the traps and their loot can be collected for free. Be sure not to place them near trees or wood.
Here is another trap that can be made with Hellstone and Cactus. Dig a line around a chosen area and every other one place sand for the Cactus to be grown on, then Hellstone to light on fire. [s][h][s][h][s] like so. Its best if you dig down one block so when you light the Hellstone on fire the flame is level with the ground. This trap is good for placing in an open area as a per-perimeter for stopping Mobs. This works excellent against spider mobs. Spiders can jump two blocks high and can jump over fire. The Cactus will stop them from being able to get through.