Pearl
A pearl is a quest item fished from the Neo-tilus region. It is most notable for its role in the Everdune questline.
Note: A quest Pearl is a different item from the oyster pearls fished up from the Valentine's Day event.
Location
Pearls can be fished from the eastern-most fishing pool, in the Neo-tilus area.
To reach this spot, the player must walk just below the entrance to Needlepoint, around a boat wreck, southeast of a Lush Chest, and finally to the pool at the end of the peninsula.
Purpose
Finnley will not-so-subtly instruct the player to fish up a pearl, sneak into the Neo-tilus museum, and swap the pearl out for a strange power source. This power source will be used to power the Everdune beacon. Once the beacon is powered, the player is granted access to the Everdune dungeon.
The pearl must be washed off in a pool in the western cave in the Everdune mountains before it can be used properly.
After the quest is completed, any spare Pearls may be banked or discarded. Pearls are not known to be a component in any crafting items.