First of all, you can explore the brush monster in the wonderful cave and have the opportunity to drop the big adventure gem.

Secondly, gems can be obtained through exchange. If you don't have enough time to explore the wonderful caves, or you have finished the exploration but still haven't got the gems, you can consider using this method.

Finally, if the above two methods can't meet your needs, you can also go to the gem dealer to collect the fragments and then exchange them to get the gems. As long as you complete the corresponding task, you can get the corresponding gem reward.

These are the routine operations and gameplay in the game. I suggest you explore more and enhance your understanding and experience of the game. Have a good game!