Currently, in Expedition, there are gems that players can find while mining. They are used mainly for currency. There are six "gems" total currently in the game. Amethyst, Sapphire, Ruby, Emerald, Gold, and Diamond are currently the gems in the game, with the exception of gold, in real life, gold is a metal.
Drop Rates: Edit
A chart was designed but was lost, will do another test and put into here eventually.
Gems can be used to dye armor.