"This treasure was supposedly a gift from roman statesman Antonius to his lover Cleopatra, Queen of Egypt."
Using the clues from the special request titled "Survey of the Depths" in their notebook, the player can find this item within the southernmost of the Twin Caves of the Zahhab Region Depths (the same cave which the Grave Keeper inhabits). In order for this treasure rumor to be activated, the player must have befriended one special Risso's Dolphin as a part of the "Be the Best Trainer!" quest.
The appraisal reward for finding this item is thirteen thousand pelagos. Nancy also gifts the player the Bio Gloves, a piece of diving equipment.