How and Why Oysters Make Pearls Both in Nature and in Captivity

Today I Found Out explains how and why oysters make pearls. The video looks at how pearls are formed naturally as well as the detailed process oyster farmers use to cultivate pearls.

Oysters make pearls as a defensive response to foreign objects. The process begins when some foreign body, such as sand, a parasite or some other organic material, manages to make its way inside the oyster’s shell and comes in contact with the mantle, a layer that protects the oyster’s internal organs, sometimes even damaging it.