Minecraft wiki entry for Unused_textures, associated text: In the versions of terrain.png used between 0.0.14a and 0.0.14a_08 there is a white texture which was not used in any in-game block. It may have been an early experimental snow texture, as Notch had stated interest in adding snow and ice before this point,[1] or it could relate to clouds, as they were added in the same version. This texture was removed from terrain.png in 0.0.15a.