why is pearl obtained from oyster spherical in shape?

Question

no guessing please. mention the source also.

Answer 1

Not all pearls are spherical.

Pearls are formed when a piece of sand or grit gets trapped inside an oyster's shell. To prevent this from irritating the oyster's soft tissues, the oyster covers it in layers of a smooth white substance, adding layer upon layer. As more layers get added, the lump becomes larger and smoother, eventually creating a pearl.

Answer 2

Look it up on google.