Cory is an Englishwoman who makes tiny detailed replicas of books, bookshelves, teapots, and the like to wear as jewelry. Some of my favorites:
Stack of books dangling earrings
Harry Potter bookshelf necklace
Incidentally, this particular item is featured in a contest right now. See the Coryographies blog entry about the contest.
There is also a graduation bookshelf necklace. See her Etsy page for the full selection.