Gramps' diamond is a quest item which is part of the Ripples quest. The quest is first given to Geralt by the friendly vodyan priest who guards the Altar to the Lady of the Lake. The item itself is obtained from Julian. Because this is a quest item, it can not be sold. During the quest, Geralt has three choices reagarding the conflict:
- he can side with the vodyanoi
- he can side with the villagers, or
- he can reconcile both sides for the Lady of the Lake
Julian, acting for the villagers, offers three different items, his Grandfather's diamond being among them, if Geralt decides to reconcile the factions.