Most people can tell you that pearls come from the sea. Far fewer can explain how they form, what types exist, or what the differences between them actually mean. Even among people who buy pearls — or sell them — the basics are often murky.
That matters, because understanding what you’re buying is the only reliable protection against buying the wrong thing. The pearl market is not straightforward. The terminology is not standardized. And the gap between what something is called and what it actually is can be significant.
Three terms appear constantly and cause the most confusion: natural, cultured, and artificial.
Artificial is the simplest. It refers to any synthetic material designed to mimic pearls — from cheap plastic beads to the more sophisticated Majorica pearls. No mollusk involved.
Cultured pearls are farmed under controlled conditions with human intervention. In an industry that has been operating for over a century, virtually 99.99% of the pearls on the market are cultured.
Natural, wild pearls are found randomly in the wild. Systematic harvesting of pearl oysters has been banned worldwide since 1958, with very limited exceptions — Bahrain being one, with strict controls on the number of oysters harvested. To find a single commercially viable natural pearl, you would need to open anywhere from ten to a hundred thousand oysters depending on the species. The ecological cost makes systematic harvesting impossible. These discoveries are accidental and extremely rare — which is why the price of even an ordinary natural pearl is high, and the price of a beautiful one is astronomical.
Both natural and cultured are classified as real pearls by the industry. Natural pearls have their own collectors and their own market — a separate realm, operating at a different scale, with prices to match.
What is a pearl?
A pearl is a solid substance that grows either in the soft mantle tissue or the gonads of a living shelled mollusk. Like its host shell, a pearl consists of nacre — aragonite (calcium carbonate) — deposited in concentric layers and bonded by an organic substance called conchiolin.
Under a microscope, the concentric layers of nacre appear as thin textured lines, similar to fingerprints. Although invisible to the naked eye, this texture produces a slight sand-like sensation when rubbed against the edge of your front teeth or another pearl — the simplest way to distinguish a real pearl from an artificial one.
Microscopically thin layers of aragonite crystals, laid in plate-like arrangements, make up the foundational structure of pearls and oyster shells. Diffraction within these layers produces the iridescent effect known as “pearl orient” or the Aurora effect. Photo: H. A. Hänni & Uni Basel.