Gems

Gems, when inserted into items, boost certain Card Attributes.

There are 8 types of gems. They start off at level 1 and can be upgraded to the next level by synthesizing 4 of the same gems of the same level.

Level 1 gems can be obtained from the Bottomless Caverns in Activity Tab. Level 2 gems can be bought from Arena Shop. Level 3 gems and higher must be synthesized.

Note: you can get a few level 3 gems and higher from Achievements rewards by completing the required tasks. Check your Achievements tab for more info.