Keshi Pearls

Even if you are an avid lover of pearl jewelry, the name “Keshi Pearl” may catch you by surprise as not many people are familiar with it. In the pearl trade, Keshi is the (Japanese) word that refers to pearls that have not been nucleated by the pearl farmer. The term “Keshi” can refer to any type of either fresh or saltwater pearl that was formed and developed without a nucleus. Today, 99.99% of all Keshi pearls are saltwater Keshi pearls. A nucleus is a small fragment of mother-of-pearl that has been smoothed and polished. Most of the production and export of nucleus’ for the entire commercial pearl industry comes from Mississippi. The nucleus is inserted into what is called the gonad of the oyster (saltwater) or the mantle of a mussel (freshwater). Following the insertion of the nucleus, is a small piece of mantle tissue from a donor oyster or mussel. The tissue that is inserted is what is responsible for the developing pearls’ color and overtones. The epithelial cells of the donor tissue is what develops the pearl sac. As the pearl sac develops, it grows around the nucleus and deposits nacre. This nacre is what ultimately results in a pearl.

Essentially, saltwater Keshi Pearls are pearls that have been developed without the insertion of a nucleus. As a result, the nacre of Keshi Pearls are thicker than other types of commercially farmed pearls and have incredible luster, they actually are the modern day equivalent of a wild pearl. Keshi Pearls sometimes develop as a result of the oyster or mussel rejecting the nucleus. this is also how a pearl would form in the wild.

A common misconception is that freshwater pearls are Keshi Pearls, this is not true. Freshwater pearls are nucleated by a pearl farmer with a soft mantle tissue (not a hard nucleus like with saltwater pearls). As a result they are considered cultured pearls - and are absolutely not Keshi. The nucleus inside of freshwater pearls decay, this results in a slight hollowness inside of freshwater pearls. Whereas a true Keshi Pearl is the result of the oyster rejecting the nucleus that was inserted. The hollowness is not what determines a Keshi Pearl from a cultured freshwater pearl, but the fact of whether the pearl was a result of the oyster being nucleated.

Because of the unique way that Keshi Pearls are developed, they have become quite rare and are in demand. Since “Keshi” describes a method of pearl development, Akoyas, Tahitian, and South Sea Pearls can all have a Keshi variety. Originally, Keshi Pearls could be found and bought for quite the bargain -this is no longer the case. Keshi Pearls are rare because pearl farmers now x-ray their oysters to determine if the nucleus has been rejected or not. If the nucleus has been rejected and therefore expelled, then a new nucleus is inserted before a Keshi Pearl is allowed to develop. As a result, Keshi Pearls are a very rare find.

In Japanese, the word “Keshi” translates to “poppy seed”. While Keshi Pearls can grow up to 10mm, quite commonly they are around 2mm. Anything smaller than 2mm or larger than 10mm is very rare. Keshi Pearls are also referred to as seed pearls. Keshi Pearls range from the classic pure white of Akoya Pearls, to exotic grays and metallic overtones of Tahitian Pearls to the rich deep golden colors of South Sea Pearls. Because there is no nucleus in the formation of Keshi Pearls, Keshi’s are almost always irregular in shape or baroque.

At Seven Seas Pearls, we are proud to display one of the largest collections of Keshi Pearls. We have always been captivated by their intense color and incredible luster. If you live in Southern California, stop by our Los Angeles Pearl Showroom. No appointment is needed and we would be delighted to show your our collection of exquisite Keshi Pearl jewelry. Present in our showroom at all times is a GIA Pearl Graduate, if you have any questions or would like to learn more about the development of Keshi Pearls, we would be happy to help. On our website you will view our some of our selection of Keshi Pearl jewelry. Each piece on our website is one of a kind and is the actual piece that you will receive. Each piece of our pearl jewelry is so unique and beautiful, that we want you to know exactly what you are receiving.