Crying Obsidian

The mystery block can only be found in the "terrain" folder, meaning that some texture pack creators might have already found this. This block has been added in Beta 1.3 but is not actually in the game. This block closely resembles Obsidian, but it still unknown as what it might be. It can also appear to be some sort of ore. A picture of the texture for the block can be seen in the link below.