--- title: "Do Pearls Come From Oysters, Clams or Mussels?" description: "Which mollusks make pearls: pearl oysters, freshwater mussels, and the clams, conchs, scallops and other mollusks that make natural pearls without nacre." canonical_url: "https://learnaboutpearls.com/science/pearl-producing-mollusks/" last_updated: "2026-11-04" last_reviewed: "2026-10-27" reviewed_by: "Simon" publisher: "Unique Pearl" publisher_disclosure: "Learn About Pearls is published by Unique Pearl, a pearl jeweler." --- # Do Pearls Come From Oysters, Clams or Mussels? **Short answer:** Pearls come from mollusks, and the pearls sold as gems come mostly from pearl oysters in the sea and freshwater mussels in lakes and ponds. Almost any mollusk can make a pearl-like object, but only species that make nacre produce the classic lustrous pearl. Clams, scallops and sea snails such as conchs also produce natural pearls, though theirs have no nacre, and many look porcelain-like instead. **Key facts:** - Almost all mollusk species can produce pearl-like objects, but the pearls valued as gems come from species that secrete nacre. [1] - Cultured pearls come from marine pearl oysters of the family Pteriidae and from freshwater pearl mussels of the families Unionidae and Margaritiferidae. [1] - Pearl oysters are marine bivalves of the genera Pinctada and Pteria. [2] - Over 98% of freshwater pearls come from China, where only about ten of more than 100 freshwater mussel species are used for pearls. [1] - Conch pearls have no nacre; their structure usually gives them a flame-like surface pattern and a porcelain-like sheen. [2] - The giant clam, Tridacna gigas, the largest and heaviest known mollusk, produces white, porcelain-like pearls. [2] All pearls come from [mollusks](https://learnaboutpearls.com/glossary/#mollusk), but not all mollusks make the pearls used in jewelry. Almost every species of mollusk can produce pearl-like objects, which scientists call [calcareous concretions](https://learnaboutpearls.com/glossary/#calcareous-concretion). The pearls valued as gems come from species that secrete [nacre](https://learnaboutpearls.com/glossary/#nacre), the material also known as [mother-of-pearl](https://learnaboutpearls.com/glossary/#mother-of-pearl). [1] Two groups of mollusks produce almost all [cultured pearls](https://learnaboutpearls.com/glossary/#cultured-pearl): marine [pearl oysters](https://learnaboutpearls.com/glossary/#pearl-oyster) of the family Pteriidae, and pearl mussels of the families Unionidae and Margaritiferidae, which live in fresh water. [1] The table shows the mollusk behind each main cultured pearl type, from the Learn About Pearls dataset. | Feature | Akoya cultured pearl | South Sea cultured pearl | Tahitian cultured pearl | Freshwater cultured pearl | | ------- | ---------------------------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------------------------ | ---------------------------------------------------------- | | Mollusk | _Pinctada fucata_ (Akoya pearl oyster) [2, 3] | _Pinctada maxima_ (silver-lipped pearl oyster and gold-lipped pearl oyster) [2, 4] | _Pinctada margaritifera cumingii_ (black-lipped pearl oyster) [2, 5, 6] | _Hyriopsis cumingii_ (triangle shell mussel) [2, 3, 7, 8] | | Water | saltwater [3, 9] | saltwater [6, 9] | saltwater [6, 9] | freshwater [2, 6] | ## Pearl oysters Pearl oysters are marine [bivalves](https://learnaboutpearls.com/glossary/#bivalve) of the genera _Pinctada_ and _Pteria_. [2] Several species have been used for pearl production for over a century: [1] - **_[Pinctada fucata](https://learnaboutpearls.com/glossary/#pinctada-fucata)_ (_P. martensii_)**, the Akoya pearl oyster, one of the smallest pearl-producing oysters, used in Japan and China for [Akoya](https://learnaboutpearls.com/glossary/#akoya) pearls. [1] - _**[Pinctada maxima](https://learnaboutpearls.com/glossary/#pinctada-maxima)**_, the largest pearl oyster, with a gold or silver lip, used for [South Sea pearls](https://learnaboutpearls.com/glossary/#south-sea-cultured-pearl). [1] - _**[Pinctada margaritifera](https://learnaboutpearls.com/glossary/#pinctada-margaritifera)**_, the black-lipped pearl oyster and the second largest, which produces the [black pearls](https://learnaboutpearls.com/glossary/#black-pearl) of French Polynesia and the Cook Islands, and is also cultured in Fiji. [1] - _**[Pteria penguin](https://learnaboutpearls.com/glossary/#pteria-penguin)**_, the winged or penguin’s wing oyster, used mainly for [mabe](https://learnaboutpearls.com/glossary/#mabe) half-pearls, and _**[Pteria sterna](https://learnaboutpearls.com/glossary/#pteria-sterna)**_, the rainbow-lipped oyster of Mexico’s Gulf of California, which now produces round and near-round cultured pearls. [1] _[Pinctada radiata](https://learnaboutpearls.com/glossary/#pinctada-radiata)_ produces [natural pearls](https://learnaboutpearls.com/glossary/#natural-pearl) in the Arabian Gulf, which CIBJO calls Bahraini or [Basra pearls](https://learnaboutpearls.com/glossary/#basra-pearl). [2] ![The inside of an oyster shell: iridescent silvery nacre with green and pink tones, edged by a dark gray-green rim and a fringe of growth scales.](/_astro/black-lipped-pearl-oyster-shell.CFOIDcNM_I3u5g.jpg?dpl=dpl_HtGtH9KVXNVAK9cLZJJhqCYEKmh2) The shell of a black-lipped pearl oyster from the Tuamotu Islands in French Polynesia, on display at the Field Museum in Chicago. Photo: “Pinctada margaritifera (black-lipped pearl oyster) (Tuamotu Islands, French Polynesia, Pacific Ocean)” by James St. John. [CC BY 2.0](https://creativecommons.org/licenses/by/2.0/), via [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Pinctada_margaritifera_\(black-lipped_pearl_oyster\)_\(Tuamotu_Islands,_French_Polynesia,_Pacific_Ocean\).jpg). ## Freshwater pearl mussels Freshwater pearl mussels are farmed in ponds, rivers and lakes. Over 98% of [freshwater pearls](https://learnaboutpearls.com/glossary/#freshwater-cultured-pearl) come from China, and the rest from countries including Japan, Australia and Vietnam. [1] China has more than 100 species of freshwater mussels, but only about ten are used for pearls. [1] The most productive is the triangle shell mussel, _[Hyriopsis cumingii](https://learnaboutpearls.com/glossary/#hyriopsis-cumingii)_, followed by _[Cristaria plicata](https://learnaboutpearls.com/glossary/#cristaria-plicata)_. China has also brought in _Hyriopsis schlegelii_ from Japan and _Potamilus alatus_ from North America, which can produce high-quality black freshwater pearls. [1] Ordinary mussels can make pearls too. CIBJO notes that the edible California mussel may contain several pearls. [2] ## Clams, conchs, scallops and other mollusks Some mollusks produce natural pearls without a nacreous surface. Clam, conch, Melo, scallop and some [pen pearls](https://learnaboutpearls.com/glossary/#pinna-pearl) are all non-nacreous. [2] - **Clams.** The northern quahog, a common North American clam, produces [clam pearls](https://learnaboutpearls.com/glossary/#clam-pearl) in shades of purple. The [giant clam](https://learnaboutpearls.com/glossary/#tridacna-gigas), _Tridacna gigas_, the largest and heaviest known mollusk, produces white, porcelain-like pearls; its two valves can weigh as much as about 225 kg. [2] - **Conchs.** [Conch pearls](https://learnaboutpearls.com/glossary/#conch-pearl) come from large sea snails such as the [queen conch](https://learnaboutpearls.com/glossary/#aliger-gigas), the horse conch and the emperor helmet. Their crossed lamellar structure usually gives them a flame-like surface pattern and a porcelain-like sheen, and they are also called pink pearls. [2] - **Melo shells.** [Melo pearls](https://learnaboutpearls.com/glossary/#melo-pearl) are [non-nacreous natural pearls](https://learnaboutpearls.com/glossary/#non-nacreous-pearl) from Melo volutes, a group of large marine snails. [2] - **Pen shells.** Pen pearls come from pen shells, marine bivalves of the family Pinnidae. They can be orange or brown, with or without nacre, or silvery and nacreous. [2] - **Scallops.** [Scallop pearls](https://learnaboutpearls.com/glossary/#scallop-pearl) have a surface made of a patchwork of tiny cells, which gives them a sheen of their own. [2] - **Abalone.** Abalone, whose nacre comes in many hues of blue, green, cream, red and purple, produces distinctive natural pearls, and [cultured blisters](https://learnaboutpearls.com/glossary/#cultured-blister) are grown in places such as California and New Zealand. [2] Natural [abalone pearls](https://learnaboutpearls.com/glossary/#abalone-pearl) are often hollow, and therefore fragile. [2] CIBJO’s entries for conch and giant clam pearls point to CITES, the international treaty that controls trade in endangered species. [2] ## How labs tell which mollusk made a pearl A pearl often carries signs of its mollusk. Usually, but not always, a natural pearl has the same color, composition and general quality as the mother-of-pearl of the mollusk that produced it. [2] Pearls from the black-lipped oyster show a reflectance feature at 700 nm that is a key identifying sign, [10] and freshwater pearls contain more manganese and barium and less strontium than [saltwater pearls](https://learnaboutpearls.com/glossary/#saltwater-pearl). [11] A GIA report states which mollusk produced a pearl when that can be determined. [3] ## Questions people ask ### Do clams make pearls? Yes, but not the nacreous pearls used in most jewelry. Clam pearls are natural pearls without nacre. The northern quahog produces them in shades of purple, and the giant clam produces white, porcelain-like ones. [2] ### Can mussels make pearls? Yes. Freshwater pearl mussels produce almost all of the world's cultured pearls by weight, mostly in China. Even the edible California mussel may contain several pearls. [1, 2] ### What is a conch pearl? A natural pearl from a large sea snail such as the queen conch. It has no nacre; its calcium carbonate is arranged in a crossed lamellar structure that usually gives it a flame-like surface pattern and a porcelain-like sheen. Conch pearls are also called pink pearls. [2] ### Which oyster makes the biggest pearls? Among the oysters used for cultured pearls, Pinctada maxima, the largest pearl oyster, produces the largest pearls, South Sea cultured pearls. [1, 12] ## References 1. Changbo Zhu, Paul C. Southgate and Ting Li (2019). Production of Pearls. [Source](https://link.springer.com/chapter/10.1007/978-3-319-96776-9_5) · DOI [10.1007/978-3-319-96776-9_5](https://doi.org/10.1007/978-3-319-96776-9_5) · [Archived copy](https://web.archive.org/web/20240129152149/https://link.springer.com/chapter/10.1007/978-3-319-96776-9_5) 2. 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) 3. Phoebe Shang (2026). Freshwater Akoyas – A Trending Misnomer for Certain Freshwater Pearls. [Source](https://www.gia.edu/freshwater-akoyas-a-trending-misnomer-for-certain-pearls) · [Archived copy](https://web.archive.org/web/20260617073835/https://www.gia.edu/freshwater-akoyas-a-trending-misnomer-for-certain-pearls) 4. 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) 5. Assemblée de la Polynésie française (Journal officiel de la Polynésie française) (2017). Loi du pays n° 2017-16 du 18 juillet 2017 réglementant les activités professionnelles liées à la production et la commercialisation des produits perliers et nacriers en Polynésie française. [Source](https://www.ressources-marines.gov.pf/wp-content/uploads/sites/24/2017/10/Loi-du-Pays-n%C2%B0-2017-16-du-18_07_2017-Activit%C3%A9s-professionnelles-perli.pdf) · [Archived copy](https://web.archive.org/web/20261026000126/https://www.ressources-marines.gov.pf/wp-content/uploads/sites/24/2017/10/Loi-du-Pays-n%C2%B0-2017-16-du-18_07_2017-Activit%C3%A9s-professionnelles-perli.pdf) 6. Gemological Institute of America (GIA), Gem Encyclopedia. Pearl Description. [Source](https://www.gia.edu/pearl-description) · [Archived copy](https://web.archive.org/web/20261017085317/https://www.gia.edu/pearl-description) 7. 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) 8. Doug Fiske and Jeremy Shepherd (2007). Continuity and Change in Chinese Freshwater Pearl Culture. [Source](https://www.gia.edu/dam/migrated-assets/docs/doc1/Continuity-and-Change-in-Chinese-Freshwater-Pearl-Culture.pdf) · DOI [10.5741/GEMS.43.2.138](https://doi.org/10.5741/GEMS.43.2.138) · [Archived copy](https://web.archive.org/web/20261025235652/https://www.gia.edu/dam/migrated-assets/docs/doc1/Continuity-and-Change-in-Chinese-Freshwater-Pearl-Culture.pdf) 9. Gemological Institute of America (GIA), FAQ. What are the main types of cultured pearls and what are their distinctive characteristics?. [Source](https://www.gia.edu/FAQ/gia-faq-about-gemstones-cultured-pearl-types-characteristics) · [Archived copy](https://web.archive.org/web/20260510233833/https://www.gia.edu/FAQ/gia-faq-about-gemstones-cultured-pearl-types-characteristics) 10. Artitaya Homkrajae (2016). Spectral Characteristics of Pinctada mazatlanica and Pinctada margaritifera Pearl Oyster Species. [Source](https://www.gia.edu/gems-gemology/summer-2016-gemnews-spectral-characteristics-pinctada-mazatlanica-margaritifera-pearl-oyster-species) · [Archived copy](https://web.archive.org/web/20260317034153/https://www.gia.edu/gems-gemology/summer-2016-gemnews-spectral-characteristics-pinctada-mazatlanica-margaritifera-pearl-oyster-species) 11. Stefanos Karampelas and others (2019). Chemical Characteristics of Freshwater and Saltwater Natural and Cultured Pearls from Different Bivalves. [Source](https://www.mdpi.com/2075-163X/9/6/357) · DOI [10.3390/min9060357](https://doi.org/10.3390/min9060357) · [Archived copy](https://web.archive.org/web/20261012102331/https://www.mdpi.com/2075-163X/9/6/357) 12. Gemological Institute of America (GIA), Gem Encyclopedia. Pearl Buyer's Guide. [Source](https://www.gia.edu/pearl/buyers-guide) · [Archived copy](https://web.archive.org/web/20260613185853/https://www.gia.edu/pearl/buyers-guide) **Written by:** Learn About Pearls editors **Fact-checked:** Learn About Pearls editors, October 26, 2026 **Reviewed by:** Simon, October 27, 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). _Do Pearls Come From Oysters, Clams or Mussels?_ Learn About Pearls. https://learnaboutpearls.com/science/pearl-producing-mollusks/ **MLA:** “Do Pearls Come From Oysters, Clams or Mussels?” _Learn About Pearls_, Unique Pearl, November 4, 2026, learnaboutpearls.com/science/pearl-producing-mollusks/. **Chicago:** Learn About Pearls editors. “Do Pearls Come From Oysters, Clams or Mussels?” Learn About Pearls. Unique Pearl. Last modified November 4, 2026. https://learnaboutpearls.com/science/pearl-producing-mollusks/. **BibTeX:** `@misc{lap-science-pearl-producing-mollusks, title = {Do Pearls Come From Oysters, Clams or Mussels?}, author = {{Learn About Pearls editors}}, year = {2026}, howpublished = {\url{https://learnaboutpearls.com/science/pearl-producing-mollusks/}}, 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 - [Nacre](https://learnaboutpearls.com/basics/nacre/): The layered material pearls and shell linings are made of, and how it differs from mother-of-pearl. - [Pearl types](https://learnaboutpearls.com/types/): Akoya, freshwater, South Sea, Tahitian and keshi pearls, and where each one comes from. - [How pearls form](https://learnaboutpearls.com/basics/how-pearls-form/): How natural and cultured pearls grow inside a mollusk, layer by layer.