The Gemstone Vault and Stained Glass Puzzle mini-events last for 2 days. You need to complete a series of levels in one of these mini-games. You can enter the mini-game via a special slot machine on the map that only appears during the mini-event.
Gemstone Vault uses Match 3 game mechanics.
The mechanics of Stained Glass Puzzle are similar to Dream Kaleidoscope.
You can enter the mini-game using keys. If you lose the game, you lose a key. You can find keys at the event location or purchase them with rubies. Once you have a new key, you can resume the game from the level where you lost.
As you progress, you will receive prizes for completing certain levels. You may get event currency, stars, and items for entering the event location. The mini-event levels are different each time.