It is just a visual glitch. The purple and black checks mean the game isn't quite sure what it is suposed to be. My guess is that it is being caused by the programming that allows 1.8 clients to connect to the server. It will probably be fine when we update. But that is just my guess. The multi-client login stuff has made a lot of glitchy inventory stuff. Like with doors and fences. There were some changes between 1.7 and 1.8 and the server is just confused as to what it should be, and is currently showing you.
If playing in 1.8, the textures are broken, also so other blocks, especially mushroom blocks. This is because they are updated in 1.8 and the texture of your client isnt the same as the server's textures. If playing on 1.7, I dont know why it is glitched out ;P Edit: got ninja'd so a couple of info is probably already listed before
I have some of those too, they seem to be a different type of oak leaf, I figured out they were different one day when selling to todd's shop.. not sure what caused it. I always held onto mine thinking it was a rare oak leaf from and older version of mc. Similar to those non-flammable wooden slabs floating around emc xD
I second this. EDIT: As Aikar said; it'll still be in the real 1.8. I guessed as much but thought I would be wrong
Actually itll be broken like that in real 1.8. It means the block has an invalid block data value, which old versions of MC could handle, but 1.8 got strict and only allows the exact correct combinations. Your best bet is to throw it out, as itll never render correctly. This is also why youll find some shop signs that say theyll buy your item but you cant sell it, due to a difference in data value, you can see on /iteminfo
Yeah I knew it was something buggy between 1.7 and 1.8. Just wasn't sure what exactly. As far as throwing it out, when you place the blocks they look normal. So you could technically build with them still. Edit: Although maybe that is a bad idea? Down the line if the blocks aren't being recognized correctly by the game or server?
Blocks given the "Missing Texture" texture will most likely not have a normal texture in the update to 1.8 thus just being an interesting black and purple combo. So yes, essentially you can throw them out as it would be useless unless you enjoy staring at them