Blue Gem Stone Chest

In-game description
Use: Obtains certain amount of gem stones. Note: The chest will be returned to system at the end of the month, please use it in time!

Additional information
This is a common chest, with the highest amount of crystals (on average) of its category. Like all crystal chests, it is best to use it once claimed, otherwise it expires after the month is over.

Content
Once opened, the player receives a random amount of crystals, which can be 6, 8, 12, 15 or 20.

Methods to obtain
The Blue Gem Stone Chest is awarded if a player successfully completes stage 1 - 4 of any chapter at the highest (purple) difficulty in story mode.