Episode 6 - Endless Winter Night
Joey and Andrea come back after defeating the Ice Queen, much to their dismay; find Tana dead. They tell Gabbie, Alex, and Tyler that they had thought wrong and actually had to choose one of them to betray, so they decided on Tana. Sireen appears and says that she is sorry for their loss, but thankful that they saved her land. In return, she says she is forever in their debt and gives them a magic crystal.
Episode 9 - The Dark Dimension
The magic crystal is seen again, in the top half of the Wizard's compass. The bottom had the Ice Gem in it.