Teal pottery vase unmarked - any ideas?

[mjm579]

Another unusual piece. Sad thing is that I swear I have seen this in a book at some point. Of course now I can't find it. Any ideas? In my opinion the cork top is not original or part of the piece. I've included it since I purchased it with the vase.

 

[mjlalt]

I think it may be a sake bottle.