I've always wondered what everyones opinion is about what's the rarest item in the game, so today I decided to make a quick poll to see. https://docs.google.com/forms/d/1p248AMWV1geu86kt9sGvaUh7GKDzwNgFNM4mIVWkZvQ/viewform
There are only a few blocks that are limited in a world. Therefore the rarest block excluding dragon egg is the end portal frame, I guess you could also count the silverfish spawner as rare, too.
The Rare items are the staff heads, and the creeper and skeli head, also to me wither skulls, coa it takes for ever to get.
lol wow i've been out of the update loop for minecraft. didn't know you could get chain mail, but that makes it still Rare in my opinion.
Easy, ICC Heads. There are only two of them in all of EMC. Behind that, sponge used in only a few places as well.