Pearls
Pearls, I believe.
Pearl (the precious object sometimes found in an oyster), is spelled thus.
Pearls are found in an oyster.
on rocks
Yes
An oyster can be found outside the back of the house, in the swimming pool.
They can be found almost any shelled mollusk such as the pearl oyster
Oyster
oyster
Pumice is neither. It is not a gem stone nor a precious stone. It is often used to clean toilets and other objects.
Columbus encountered Taino people when he and his men first landed. When he went to more islands nearby, he found gold and precious objects.
pearl