Pearl Terms

The world of pearls comes with its very own highly specific language, so here’s a quick guide to understanding some of the technical terms used.
  • Bivalve: Used in the pearl industry to describe either a mussel (freshwater) or an oyster (saltwater). 
  • Baroque: An asymmetrical pearl shape that is non-spherical and imperfect. Baroque pearls can range from slight aberrations to being highly irregular in shape. 
  • Keshi: The Japanese word for poppy, Keshi pearls are a unique byproduct of the culturing process. A Keshi pearl is typically defined as a “seedless” pearl, meaning that there is no nucleus.
  • Maeshori: The Japanese word for a pre-treatment process that is extensively used for Akoya pearls, where surface impurities are removed and luster is enhanced. 
  • MOP (Mother-of-Pearl): The host shell of a pearl, which is typically used for craftwork and ornaments. 
  • Mabe: The Japanese term for a pearl that is hemispherical, usually grown on the inside of the shell mantle. 
  • Nucleus: The minute spherical ball (usually made of organic shell matter) that is implanted by the pearl farmer in order to create a cultured pearl. 
  • Luster: The amount of light reflected by a pearl. The higher the luster, the greater the pearl shines back. When paired with a clean surface, the optical effect of luster is further enhanced and a sharp mirror-like appearance is visible. 
  • Nacre: The “pearly substance” naturally produced by a bivalve. Nacre is a liquid crystal structure that slowly coats the nucleus layer-by-layer to create a pearl. 
  • Cultured Pearl: Any pearl that is created intentionally by man, typically through a pearl farmer’s intentional intervention. 
  • Hatchery: A section of the pearl farm dedicated to breeding oysters, typically on-shore. The hatchery is critical to sustainably managing oyster populations. 
  • Collar: Typically a necklace of 16 inches that is worn tight around the neck. It is sometimes referred to as a choker.
  • Classic: Necklace of 18 inches or more.
  • Double: Typically a necklace of 32-36 inches, which can be worn without a clasp. 
  • Rope: Necklace of 48 inches or more.