Pearl NFTs also have a rarity system with various traits and can be traded. You can use Pearls to boost your yield in the Clam Island Bank (=yieldfarm). Depending on the rarity of the Pearl, the boost in the yieldfarm will be higher.
Each Pearl produced by a Clam has a randomized set of attributes, like Shape, Bodycolor, Overtone, Size, Lustre, Nacre Quality and Surface.
How those Traits look like and how likely or rare their setting can be, is explained in the Pearl Traits section below.
Clams will have higher chances of generating Pearls with rarer traits towards the end of its lifespan. Its lifespan is dictated by the amount of Pearls the Clam can produce (one of its randomized traits), rather than a period of time. Once the last Pearl is produced, the Clam dies.
Once the Pearl is produced, you will need to claim it from the Pearl Farm. In doing so, the 5 $GEM attached to the Clam will be spent (again 80% burned and 20% to treasury). From the gamification perspective, this is generating intrinsic value into the Pearl produced.
If you want to continue producing Pearls, then you attach another 5 $GEM to the Clam, and stake it back into the Pearl Farm.