Pearl Valued for their use as jewelry, pearls form within oysters a foreign particle that the oyster treats as a threat. (more) How Do Oysters Make Pearls? Ask the Chatbot a Question More Actions Share Share Share to social media Facebook X URL https://www.britannica.com/science/How-Do-Oysters-Make-Pearls Feedback Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). Feedback Type Select a type (Required) Factual Correction Spelling/Grammar Correction Link Correction Additional Information Other Your Feedback Submit Feedback Thank you for your feedback Our editors will review what you’ve submitted and determine whether to revise the article.

　　External Websites Ask the Chatbot a Question Written and fact-checked by The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors. The Editors of Encyclopaedia Britannica Last Updated: Apr 8, 2025 • Article History Table of Contents Table of Contents Ask the Chatbot The pearl-making process begins when a foreign particle, like a grain of sand or a tiny parasite, finds its way into the oyster’s shell. This uninvited guest irritates the oyster, much like a pebble in a shoe. To protect itself, the oyster’s mantle tissue, which is responsible for shell formation, starts to secrete nacre, also known as mother-of-pearl, around the irritant. This material, made largely of aragonite (CaCO3) but also conchiolin, a hornlike organic substance that is the main constituent of the mollusk’s outer shell. The oyster continues to coat the particle with layers of nacre over time. This process ...(100 of 218 words)

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