Often highly iridescent, the irregular baroque shape of Keshi Pearls is intriguing.
The name Keshi comes from the Japanese word for poppy seed. Originally, these pearls were small 'chance' pearls produced while the main cultured pearl was forming. Today, Keshi typically refers to larger 'chance' pearls created in the giant Pinctada oyster shells. These larger 'chance' pearls are sometimes up to 10 millimeters in size.
These pearls are formed when an oyster rejects the implanted nucleus before the culturing process is complete. The result is an irregularly shaped pearl without a nucleus. Keshi Pearls tend to have high luster as they do not contain a nucleus and are 100% nacre.
Keshi Pearls were once regarded as a bargain; however, many farmers now x-ray the oyster shells to make sure the implanted nucleus is still inside. If it is not, the oyster is re-nucleated before the Keshi Pearl is able to form. As a result, these pearls are now even rarer to come by, making them much more expensive than they once were.
These pearls come from both saltwater and freshwater mollusks, and are generally smaller in size because they do not have a nucleus to guide their shape during formation.