Crystal Berry
The Crystal Berry is a glittering berry made of crystal in Paper Mario. Mario recieves it from Posie in order to trade it with the Water Stone that's in Rosie's possession.
Posie is connected at the roots to the Crystal Tree, and she shakes the tree to make a Crystal Berry fall out. According to Rosie, the Crystal Berry is more beautiful than the Water Stone, and she will eagerly give the stone to Mario for the berry. The whole point of this trading sequence is to give the Water Stone back to Lily so she can refill her pond before she drys up.
Unlike the other berries Mario finds in Flower Fields, there is only one Crystal Berry and Rosie won't give it back once Mario gives it to her.
The Crystal Tree and Posie's area is at the end of the south western path of Flower Fields.
