Player: Blue
Character: Cinderella (Rarity)
Reason for Echo: Tainted water consumption.
What is returned: The geode that the breaking-open of which triggered the reveal of Rarity's cutie mark; in tact it looks like nothing but a large rock, about twice her height and as wide as she is long across - it is hollow and lined inside with likely cheap but very colorful crystals, which little Rarity had gotten harvested and implemented into her first extra-special-personal-touch set of costumes.