Fetch a Philosopher's Stone for Jack (Or Keep It)

See also: Jack Pott Intentions

Jack asked you to look into getting a philosopher's stone the same way (transporting it out of the Written Realms) from somewhere in the north sections of the Library (either Mystery, Magical Reference, or Philosophy/Religion). Whether you sell it to him or not, he will happily accept any gold the stone generates and has promised a secret menu of expensive items.