Originally Posted by
cupcakes4cece
I always advise new players to play until they get to Trinity Island and then just stay there forever. I like Trinity Island specifically because it seems to give each of the necklaces pretty evenly, so you don't end up with a huge number of one item and very few of another other.
Other gem-earning islands are Falcon Island, Misty Rock, Abandoned Quarry, Tribal Council, and Deadly Straights. All give Precious Materials.
The only other island to give Incan Necklaces is Secret Lagoon.