End Stone

Ender Sand is a new block that appears in The End and makes up the surface of the world. It appears as a white block with a mottled texture that can be found in the 1.9 pre-release 3 terrain.png underneath the Air Portal and Air Portal Frame textures. Ender Sand can only be successfully mined with a Pickaxe and will drop Cobblestone like normal stone.

Trivia

 * The texture is likely to just be a brightened version of the Cobblestone texture.
 * In Minecraft 1.9 Pre-release 4, when mining Ender sand you get Cobblestone.