Gem Trees are special trees on the explorer's home island that grow gems. Each explorers home island is randomly provided with one tree of the five different gems. Every 24 hours, these trees provide one gem and the opportunity to share a limited number of gems with their neighbors to the player and all of their neighbors .
Now you can even get Gem Fruit from your tree. Gem Fruit give 10 Energy as well as a random Gem. When harvested, you can share some Gem Fruit on the News Feed. Gem Fruit do expire after a few days, but even expired Gem Fruit give a random Gem when you "toss" them.