Islebound: Emerald Edition is a special edition of the game with some altered components and rules. It's best to think of it as a variant of the game, rather than a 2nd edition. This edition removes the book resource from the original game and replaces it with emeralds. Emeralds have different uses than books. You collect them when visiting a player-owned town and when you taking over a town. Emeralds must be used to buy building cards, and they can also be used to perform special abilities, such as keeping pirates and serpents after combat!
When we brought out the board and asked 'Should people play with Ouija boards?', the response we got was 'ask again later'. We then had to inform it that it was not, in fact, a magic 8 ball. Poor ghost.