--- title: "How Do You Identify Pearls and Their Treatments?" description: "How pearls are identified: telling pearls from imitations, natural from cultured, saltwater from freshwater, and spotting treatments, plus what labs test." canonical_url: "https://learnaboutpearls.com/identification/" 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." --- # How Do You Identify Pearls and Their Treatments? **Short answer:** Identifying a pearl means answering three questions: is it a pearl or an imitation, is it natural or cultured, and has it been treated? Some checks are simple. In a GIA study, cultured pearls felt gritty against the teeth while imitations felt smooth. But separating natural from cultured pearls, or saltwater from freshwater, and finding most treatments takes a gem laboratory, with X-ray imaging, spectroscopy and chemical analysis. A pearl’s identity decides how it may be described and much of what it is worth. This section covers the tests used, from the simple to the ones only a laboratory can run. ## Pearl or imitation An [imitation pearl](https://learnaboutpearls.com/glossary/#imitation-pearl) is a manufactured product that only looks like a pearl or a [cultured pearl](https://learnaboutpearls.com/glossary/#cultured-pearl). [1] One widely sold kind, made on the Spanish island of Majorca, is a glass bead coated in layers of “[pearl essence](https://learnaboutpearls.com/glossary/#pearl-essence)” made from fish scales. [2] GIA researchers who studied those imitations found four tests conclusive for separating them from cultured pearls: refractive index, magnification, [X-radiography](https://learnaboutpearls.com/glossary/#x-radiography) and the [tooth test](https://learnaboutpearls.com/glossary/#tooth-test). [2] In the tooth test, the cultured pearls they tested felt gritty and the imitations smooth. [2] In the United States, an imitation must be called “imitation”, “artificial” or “simulated” whenever the word “pearl” is used. Names such as “faux pearl” and “fashion pearl” need the same qualifier. [1] The page [how to tell if pearls are real](https://learnaboutpearls.com/identification/how-to-tell-if-pearls-are-real/) explains each check, and [real vs imitation pearls](https://learnaboutpearls.com/compare/real-vs-imitation-pearls/) what imitations are made of. ## Natural or cultured Telling a [natural pearl](https://learnaboutpearls.com/glossary/#natural-pearl) from a cultured pearl takes a laboratory. X-ray radiography and [X-ray computed microtomography](https://learnaboutpearls.com/glossary/#computed-microtomography) are central to the work, [3] because a natural pearl shows no bead or curved cavity at its center and a uniform, onion-like structure. [4] The [natural pearls](https://learnaboutpearls.com/natural-pearls/) section explains why this matters. ## Saltwater or freshwater The water a pearl grew in shows in its chemistry. [Freshwater pearls](https://learnaboutpearls.com/glossary/#freshwater-cultured-pearl) contain more manganese and barium, and less strontium, than [saltwater pearls](https://learnaboutpearls.com/glossary/#saltwater-pearl). [5] A GIA report states whether pearls grew in freshwater or saltwater, and which [mollusk](https://learnaboutpearls.com/glossary/#mollusk) produced them when that can be determined. [6] ## Treatments Pearls might be dyed, impregnated or coated, and some are bleached or irradiated. GIA notes that [bleaching](https://learnaboutpearls.com/glossary/#bleaching) and [irradiation](https://learnaboutpearls.com/glossary/#irradiation) can be stable during normal wear. [7] Examples include irradiated gray or blue [Akoya](https://learnaboutpearls.com/glossary/#akoya), whose [shell bead](https://learnaboutpearls.com/glossary/#bead) darkens inside, [8] and dyed “golden” cultured pearls, some of which show little sign of the dye on the surface. [9] Treatments must be disclosed. CIBJO’s standards require a treatment such as bleaching, [dyeing](https://learnaboutpearls.com/glossary/#dyeing), [coating](https://learnaboutpearls.com/glossary/#coating), [heating](https://learnaboutpearls.com/glossary/#heating) or irradiation to be named next to the words “cultured pearl” and explained to the buyer before the sale closes. [10] French Polynesia’s pearl law requires [treated pearls](https://learnaboutpearls.com/glossary/#treated-pearl) to be labeled as treated. [11] The page [dyed and treated pearls](https://learnaboutpearls.com/identification/dyed-and-treated-pearls/) covers each treatment and how labs find it. ## What a laboratory tests GIA has identified and classified natural and cultured pearls since 1949. [12] Its gemologists identify the pearl type, the mollusk and any detectable treatments with standard gem testing and with real-time X-radiography, UV-Vis reflectance spectroscopy and X-ray fluorescence, and use computed microtomography when a loose pearl needs more detailed analysis. [12] SSEF’s reports likewise separate natural from cultured pearls, beaded from beadless, and saltwater from freshwater, and indicate treatments. [13] ## Start here 1. [Is it a real pearl?](https://learnaboutpearls.com/identification/how-to-tell-if-pearls-are-real/) 2. [Dyed and treated pearls](https://learnaboutpearls.com/identification/dyed-and-treated-pearls/) ## Every page in this section - [Is it a real pearl?](https://learnaboutpearls.com/identification/how-to-tell-if-pearls-are-real/) Simple checks that point to an imitation, what each one can and can't prove, and when to ask a lab. - [Dyed and treated pearls](https://learnaboutpearls.com/identification/dyed-and-treated-pearls/) The common pearl treatments, from bleaching and dyeing to irradiation, and how labs detect them. ## References 1. 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) 2. June Hanano, Mary Wildman and Philip G. Yurkiewicz (1990). Majorica Imitation Pearls. [Source](https://www.gia.edu/doc/Majorica-Imitation-Pearls.pdf) · DOI [10.5741/GEMS.26.3.178](https://doi.org/10.5741/GEMS.26.3.178) · [Archived copy](https://web.archive.org/web/20251005124434/https://www.gia.edu/doc/Majorica-Imitation-Pearls.pdf) 3. Chunhui Zhou and W. Henry Towbin (2024). Applications of X-Ray Radiography and X-Ray Computed Microtomography in Gemology. [Source](https://www.gia.edu/gems-gemology/winter-2024-x-ray-imaging) · DOI [10.5741/GEMS.60.4.582](https://doi.org/10.5741/GEMS.60.4.582) · [Archived copy](https://web.archive.org/web/20260313113455/https://www.gia.edu/gems-gemology/winter-2024-x-ray-imaging) 4. 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) 5. 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) 6. 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) 7. 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) 8. Emiko Yazawa and Chunhui Zhou (2024). Irradiated and Dyed Akoya Pearls. [Source](https://www.gia.edu/gems-gemology/spring-2024-lab-notes-irradiated-and-dyed-akoya-pearls) · [Archived copy](https://web.archive.org/web/20240720120748/https://www.gia.edu/gems-gemology/spring-2024-lab-notes-irradiated-and-dyed-akoya-pearls) 9. Chunhui Zhou, Artitaya Homkrajae, Joyce Wing Yan Ho, Akira Hyatt and Nicholas Sturman (2012). Update on the Identification of Dye Treatment in Yellow or "Golden" Cultured Pearls. [Source](https://www.gia.edu/gems-gemology/winter-2012-cultured-pearls-zhou) · DOI [10.5741/GEMS.48.4.284](https://doi.org/10.5741/GEMS.48.4.284) · [Archived copy](https://web.archive.org/web/20260309094817/https://www.gia.edu/gems-gemology/winter-2012-cultured-pearls-zhou) 10. 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) 11. 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) 12. Gemological Institute of America (GIA), Analysis & Grading. How GIA Identifies and Classifies Pearls. [Source](https://www.gia.edu/gem-lab-how-gia-identifies-classifies-pearls) · [Archived copy](https://web.archive.org/web/20260606232640/https://www.gia.edu/gem-lab-how-gia-identifies-classifies-pearls) 13. Swiss Gemmological Institute SSEF. Pearls (SSEF reports). [Source](https://www.ssef.ch/reports/pearls/) · [Archived copy](https://web.archive.org/web/20260611191437/https://www.ssef.ch/reports/pearls/) **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). _How Do You Identify Pearls and Their Treatments?_ Learn About Pearls. https://learnaboutpearls.com/identification/ **MLA:** “How Do You Identify Pearls and Their Treatments?” _Learn About Pearls_, Unique Pearl, November 4, 2026, learnaboutpearls.com/identification/. **Chicago:** Learn About Pearls editors. “How Do You Identify Pearls and Their Treatments?” Learn About Pearls. Unique Pearl. Last modified November 4, 2026. https://learnaboutpearls.com/identification/. **BibTeX:** `@misc{lap-identification, title = {How Do You Identify Pearls and Their Treatments?}, author = {{Learn About Pearls editors}}, year = {2026}, howpublished = {\url{https://learnaboutpearls.com/identification/}}, 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 - [Natural pearls](https://learnaboutpearls.com/natural-pearls/): Pearls that formed with no human help, why they are rare, and how labs confirm them. - [Grading](https://learnaboutpearls.com/grading/): Why there is no single pearl grading system, and how labs, governments and the trade grade pearls. - [Science](https://learnaboutpearls.com/science/): How mollusks build nacre, why pearls shine, and how labs read a pearl's origin from its chemistry and structure.