Layer of blood-red blocks above bedrock. It's 4 times harder and more resistant than Obsidian, making it a great building material to protect agaisnt Creepers or Bombskits. Its main purpose, however, is to hide the Goddess Ore hidden beneath this layer.
Unobtainium Ore (The Core, 2003 Film)
Tier-8 material. Can be used to make armour and a sword and pickaxe. Requires at least Adamantium Tools to mine.