Pearls are the only gemstones made by living creatures. Mollusks produce pearls by depositing layers of calcium carbonate around microscopic irritants—usually a grain of sand, as it’s commonly believed—that get lodged in their shells.
While any shelled mollusk can technically make a pearl, only two groups of bivalve mollusks (or clams) use mother-of-pearl to create the iridescent “nacreous” pearls that are valued in jewelry. These rare gemstones don’t require any polishing to reveal their natural luster.
Appropriately, the name “pearl” comes from the Old French perle, from the Latin perna meaning “leg,” referencing the leg-of-mutton shape of an open mollusk shell.
The finest pearls have a naturally reflective luster, making them appear creamy white with an iridescent sheen that casts many colorful hues. Cultured freshwater pearls can also be dyed yellow, green, blue, brown, pink, purple or black.
Black pearls—which are mostly cultured because they are so rare in nature—aren’t actually black but rather green, purple, blue or silver.
Pearls used to be found in many parts of the world, but natural pearling is now confined to the Persian Gulf waters near Bahrain. Australia owns one of the world’s last remaining pearl diving fleets and still harvests natural pearls from the Indian Ocean.
Today, most freshwater cultured pearls come from China. South Sea pearls are cultured along the northwestern coastline of Australia, the Philippines, and Indonesia.
-Clean your pearls with a soft cloth after each wear. This helps to prevent the buildup of oils and other material from handling.
-If pearls become stained, clean with lukewarm water and baking soda with a soft cleaning cloth. Never submerge a pearl necklace in water as this will weaken the silk strand.