Pearl

Pearls are a rare item that can be caught while Fishing on any island. They can be used to upgrade perks and purchase certain equipment. There are three types of pearls, with the higher rarity pearls being increasingly rarer.

Rough Pearl -
Polished Pearl -
Pristine Pearl -

The chance to catch a pearl can be increased by multiple factors:

Glimmering Tide Active on any climate
Glimmering Winds Active on any island
Fishing Spot with the Glimmering Hook buff
Fishing Spot with the Pearl Magnet buff