--- title: "Keshi Pearls: What They Are and How They Form" description: "Keshi are cultured pearls with no bead, formed on Akoya, South Sea and Tahitian pearl farms: how they form, their sizes and shapes, and how labs identify them." canonical_url: "https://learnaboutpearls.com/types/keshi-pearls/" last_updated: "2026-11-04" last_reviewed: "2026-10-26" reviewed_by: "Simon" publisher: "Unique Pearl" publisher_disclosure: "Learn About Pearls is published by Unique Pearl, a pearl jeweler." --- # Keshi Pearls: What They Are and How They Form **Short answer:** Keshi pearls are saltwater cultured pearls that grow without a bead, as a by-product of bead culturing in Akoya, South Sea and Tahitian pearl oysters. They form when an oyster rejects its bead or a scrap of grafted tissue makes its own pearl sac, and many are now grown on purpose. Mostly solid nacre and usually baroque or button-shaped, they range from under 1 mm to 16 mm. | Mollusk | _Pinctada maxima_, _Pinctada margaritifera cumingii_ and _Pinctada fucata_ (South Sea, black-lipped and Akoya pearl oysters) [1, 2] | | ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------ | | Water | saltwater [1] | | Natural or cultured | cultured [1, 3] | | Main producing regions | wherever South Sea, Tahitian and Akoya cultured pearls are farmed [1] | | Size range | under 1 mm to 16 mm (larger ones are very rare) [3, 4] | | Shapes | baroque, button, oval and drop [1, 5, 6] | | Natural colors | white to yellow and gray to black [1, 6] | | Nacre | No bead, and mostly solid nacre. Some South Sea and Tahitian keshi are hollow or contain a lot of organic matter. [1, 2] | **Key facts:** - Keshi is Japanese for "poppy seed". The word first described the tiny pearls found when Akoya cultured pearls were harvested. [3, 4] - Keshi range from under 1 mm to 16 mm, and larger ones are very rare. [4] - Keshi are mainly composed of solid nacre, like natural pearls, though some South Sea and Tahitian keshi are hollow or rich in organic matter. [1, 2] - CIBJO says the word "keshi" on its own has been misused, and should be qualified as natural or cultured. [1] - SSEF's reports call them beadless cultured pearls, and GIA's reports don't use the word keshi. [2, 5] - Most keshi are believed to grow in the oyster's gonad, while natural pearls form mainly in the mantle. [6] A [keshi](https://learnaboutpearls.com/glossary/#keshi) is a [cultured pearl](https://learnaboutpearls.com/glossary/#cultured-pearl) that grew without a bead in an oyster farmed for [bead-cultured pearls](https://learnaboutpearls.com/glossary/#beaded-cultured-pearl). [1] CIBJO’s term for it is a keshi cultured pearl. ## How keshi pearls form Keshi form as a by-product of pearl culturing. A [pearl sac](https://learnaboutpearls.com/glossary/#pearl-sac) can grow from an injury to the [mantle](https://learnaboutpearls.com/glossary/#mantle) during handling, from part of the grafted tissue, or from the whole [graft](https://learnaboutpearls.com/glossary/#graft) after the oyster rejects its bead, and the sac then makes a pearl with no bead. [1] Keshi used to be seen mostly as by-products, but today they are also grown on purpose on pearl farms. [6] Either way they are cultured, not natural: CIBJO defines them as forming, accidentally or on purpose, through human intervention. [1] ## Where keshi pearls come from Keshi come from the same oysters as bead-cultured pearls: the [Akoya](https://learnaboutpearls.com/glossary/#akoya) oyster, _[Pinctada maxima](https://learnaboutpearls.com/glossary/#pinctada-maxima)_, the black-lipped _[Pinctada margaritifera](https://learnaboutpearls.com/glossary/#pinctada-margaritifera)_ and _[Pinctada radiata](https://learnaboutpearls.com/glossary/#pinctada-radiata)_. CIBJO gives the main ones their own names, Akoya keshi, South Sea keshi and Tahitian keshi cultured pearls. [1] The first keshi were small, near-round nacreous pearls from Japanese Akoya oysters, usually about 2 mm or smaller. [3] The term was later applied to large [beadless cultured pearls](https://learnaboutpearls.com/glossary/#non-beaded-cultured-pearl) formed in the [gonads](https://learnaboutpearls.com/glossary/#gonad) of South Sea and Tahitian oysters. [5] The term covers marine [pearl oysters](https://learnaboutpearls.com/glossary/#pearl-oyster) only. Similar by-products of freshwater culture in the United States are called [Lagniappe cultured pearls](https://learnaboutpearls.com/glossary/#lagniappe-cultured-pearl), from a word used in southern Louisiana for a little bonus. [1] ## Keshi sizes, shapes and colors Keshi range from under 1 mm to 16 mm (larger ones are very rare) [4]. Keshi from the large South Sea oyster are bigger than the original Akoya keshi. [4] Their shapes are baroque, button, oval and drop [1]. CIBJO describes keshi as essentially [baroque](https://learnaboutpearls.com/glossary/#baroque), and SSEF found perfectly round ones rare. [1, 5] The page [baroque pearls](https://learnaboutpearls.com/types/baroque-pearls/) explains the shape. In a 2026 GIA study of 43 South Sea keshi from an Australian farm, most were [button-shaped](https://learnaboutpearls.com/glossary/#button-shaped), with a flat or concave base. [6] CIBJO describes their colors as white to yellow and gray to black [1]. ## Why keshi are mostly solid nacre With no bead inside, keshi are mainly composed of solid [nacre](https://learnaboutpearls.com/glossary/#nacre), like [natural pearls](https://learnaboutpearls.com/glossary/#natural-pearl). [2] Some South Sea and Tahitian keshi are hollow or contain a lot of organic matter. [1] ## How labs identify keshi pearls Telling keshi from natural pearls can be hard. X-ray imaging shows organic-rich centers, voids or lines instead of a bead, and because some of these features also occur in natural pearls, a few results are inconclusive. [2] GIA’s 2026 study found that the internal features of some South Sea keshi closely resemble those of natural pearls. [6] The difference matters for value. In 2010, SSEF warned that beadless cultured pearls from South Sea oysters, some sold with reports calling them natural, were entering the natural pearl trade, and that some traders were picking out the ones with the most confusing internal structures. [5] Most keshi are believed to grow in the oyster’s gonad, while natural pearls form mainly in the mantle. [6] ## What to call keshi pearls Because the word has been misused, CIBJO says “keshi” should always be qualified, as in “keshi cultured pearl”. [1] SSEF writes “beadless cultured pearl” on its reports instead, [5] and GIA’s reports don’t use the word either. [2] GIA’s research articles call them non-bead cultured pearls. In the United States, any cultured pearl must be described as “cultured” whenever the word “pearl” is used. [7] ## Questions people ask ### Are keshi pearls natural? No. Keshi are cultured pearls, because they form only after people operate on the oyster, even when the pearl itself forms by accident. CIBJO defines the keshi cultured pearl as a non-beaded cultured pearl formed, accidentally or on purpose, by human intervention. [1] ### What does keshi mean? It is Japanese for "poppy seed", a reference to the tiny size of the first keshi, found in Akoya oysters. [2, 4] ### Do keshi pearls have a bead? No. A keshi has no bead and is mainly solid nacre, though some are hollow or have an organic-rich center. [1, 2] ### How big are keshi pearls? From under 1 mm to 16 mm, and larger ones are very rare. Akoya keshi are usually about 2 mm or smaller, while keshi from the larger South Sea oyster are bigger. [3, 4] ### Can keshi pearls be mistaken for natural pearls? Yes. Some keshi have internal structures much like those of natural pearls, which makes them hard to identify, and SSEF warned in 2010 that beadless cultured pearls were entering the natural pearl trade. A gem laboratory can usually tell them apart, though a few results are inconclusive. [2, 5, 6] ## References 1. CIBJO, The World Jewellery Confederation, Pearl Commission (2026). The CIBJO Pearl Book (Pearl Blue Book) 2026. [Source](https://cibjo.org/wp-content/uploads/2026/10/Pearl-Blue-Book-2026-.pdf) · [Archived copy](https://web.archive.org/web/20261025235254/https://cibjo.org/wp-content/uploads/2026/10/Pearl-Blue-Book-2026-.pdf) 2. Artitaya Homkrajae, Nanthaporn Nilpetploy, Areeya Manustrong, Nicholas Sturman, Kwanreun Lawanwong and Promlikit Kessrapong (2021). Internal Structures of Known Pinctada maxima Pearls: Cultured Pearls from Operated Marine Mollusks. [Source](https://www.gia.edu/gems-gemology/fall-2021-internal-structures-pinctada-maxima-pearls) · DOI [10.5741/GEMS.57.3.186](https://doi.org/10.5741/GEMS.57.3.186) · [Archived copy](https://web.archive.org/web/20260420034834/https://www.gia.edu/gems-gemology/fall-2021-internal-structures-pinctada-maxima-pearls) 3. H. A. Hänni (2006). A short review of the use of "keshi" as a term to describe pearls. [Source](https://www.ssef.ch/wp-content/uploads/2018/03/2006_Haenni_A_short_review_of_the_use_of_Keshi_as_a_term_to_describe_pearls.pdf) · DOI [10.15506/JoG.2006.30.1.51](https://doi.org/10.15506/JoG.2006.30.1.51) · [Archived copy](https://web.archive.org/web/20260416052623/https://www.ssef.ch/wp-content/uploads/2018/03/2006_Haenni_A_short_review_of_the_use_of_Keshi_as_a_term_to_describe_pearls.pdf) 4. CIBJO Pearl Commission (2025). CIBJO Guides Describing and Classifying Natural and Cultured Pearls, the Producing Molluscs & Responsible Pearling. [Source](https://cibjo.org/wp-content/uploads/2025/12/Final-Guide-October-2025-v2-COMPRESSED.pdf) · [Archived copy](https://web.archive.org/web/20260212155210/https://cibjo.org/wp-content/uploads/2025/12/Final-Guide-October-2025-v2-COMPRESSED.pdf) 5. Michael S. Krzemnicki (2010). Trade Alert: "Keshi" cultured pearls are entering the natural pearl trade. [Source](https://www.ssef.ch/wp-content/uploads/2017/12/newsletter_pearl_2010May-1.pdf) · [Archived copy](https://web.archive.org/web/20261026000024/https://www.ssef.ch/wp-content/uploads/2017/12/newsletter_pearl_2010May-1.pdf) 6. Nishka Vaz, Abeer Al-Alawi and Anukul Belanke (2026). Diverse Range of Organic-Rich Cores in South Sea Non-Bead Cultured "Keshi" Pearls. [Source](https://www.gia.edu/gems-gemology/spring-2026-organic-rich-cores-in-south-sea-keshi-pearls) · DOI [10.5741/GEMS.62.1.26](https://doi.org/10.5741/GEMS.62.1.26) · [Archived copy](https://web.archive.org/web/20261025235759/https://www.gia.edu/gems-gemology/spring-2026-organic-rich-cores-in-south-sea-keshi-pearls) 7. U.S. Federal Trade Commission (Electronic Code of Federal Regulations). 16 CFR Part 23, Guides for the Jewelry, Precious Metals, and Pewter Industries. [Source](https://www.ecfr.gov/current/title-16/chapter-I/subchapter-B/part-23) · [Archived copy](https://web.archive.org/web/20260907072405/https://www.ecfr.gov/current/title-16/chapter-I/subchapter-B/part-23) **Written by:** Learn About Pearls editors **Fact-checked:** Learn About Pearls editors, October 26, 2026 **Reviewed by:** Simon, October 26, 2026 **First published:** November 4, 2026 **Publisher:** [Unique Pearl](https://learnaboutpearls.com/about/), a pearl jeweler **Revision history** 1. November 4, 2026: First published. First published **How to cite this page** **APA:** Learn About Pearls editors. (2026). _Keshi Pearls: What They Are and How They Form_. Learn About Pearls. https://learnaboutpearls.com/types/keshi-pearls/ **MLA:** “Keshi Pearls: What They Are and How They Form.” _Learn About Pearls_, Unique Pearl, November 4, 2026, learnaboutpearls.com/types/keshi-pearls/. **Chicago:** Learn About Pearls editors. “Keshi Pearls: What They Are and How They Form.” Learn About Pearls. Unique Pearl. Last modified November 4, 2026. https://learnaboutpearls.com/types/keshi-pearls/. **BibTeX:** `@misc{lap-types-keshi-pearls, title = {Keshi Pearls: What They Are and How They Form}, author = {{Learn About Pearls editors}}, year = {2026}, howpublished = {\url{https://learnaboutpearls.com/types/keshi-pearls/}}, note = {Learn About Pearls, published by Unique Pearl}}` Quoting with attribution and a link is welcome. See [how to cite and reuse](https://learnaboutpearls.com/cite/). **Suggest a correction** ## Related pages - [South Sea pearls](https://learnaboutpearls.com/types/south-sea-pearls/): The largest cultured pearls, white to golden, from the Pinctada maxima oyster. - [Tahitian pearls](https://learnaboutpearls.com/types/tahitian-pearls/): Dark, naturally colored cultured pearls from the black-lipped oyster of French Polynesia. - [Natural pearls](https://learnaboutpearls.com/natural-pearls/): Pearls that formed with no human help, why they are rare, and how labs confirm them.