Pearls within a pearl oyster shell. Pearl oysters are important products in Japan, as they produce beautiful pearls that are sought after for necklaces, earrings, and rings. Disclaimer: AAAS and ...

A pearl does not begin as something precious. It begins as a problem. Inside an oyster, a tiny particle slips in and settles where it does not belong. It might be a parasite, a rough fragment, or ...