Crying Obsidian

Mystery block refers to an abandoned project by Jeb that can only be found in the form of a texture in "terrain.png". This block has been added in Beta 1.3 but is currently not used in the game. This block closely resembles Obsidian, but it's still unknown as what it might be. It can also appear to be some sort of ore or slightly resembles Netherrack. There is no indication yet as to whether this block will be implemented in future.