[Hadrian]

Oh, the crystals are fir the summer event. If you look at the bottom of the page there is a "join the fight" button. You can battle other players in a game similar to rock paper scissors but cooler and more numerous options. When you win you receive "queen's pearls" when you lose you get crystals. You can also get crystals and pearls from posting like you already saw. Now these jewel things are currency for the event store when you can trade them in for cool event themed items. Does that help any?