Diamonds named with Anvil can't be used for crafting?

I renamed a Diamond with an anvil in Survival mode to put in a friends chest as a joke, then I tried using the diamond to make a pickaxe and the game won't recognize it as a diamond. So, I renamed 8 more with the same name and tried making those specific ones into a diamond block, and that didn't work either. So, now I have 9 diamonds that can't be used for crafting. I even went to the anvil and deleted their names to give them the default name and they still don't work amd cant be mixed with the rest of the diamonds I have on this server. Help please!