Pearls are the gemstones of the sea, the “birthstone” of June and a metaphor for the rare and valuable. Let me explain to you how pearls are made, what types there are and how to tell them apart.

The English word “pearl” comes from the French “perle” but is actually originally from the Latin “perna”, meaning leg.

Pearls are hard glistening objects produced by living shelled mollusks. Perfectly round pearls are the rarest and most valuable shape but pearls come 7 more different shapes: semi-round, button, drop, pear, oval, baroque, circled and double bouldered. The iridescence of pearls is caused by the overlapping of successive layers, which break up light falling onto the luster. The best pearls have a mirror-like luster but they can be dyed in any color.

The preferred weight measure used for loose pearls and pearl strands is momme, it’s a weight measure used by the Japanese for centuries. Today, it’s still the standard unit of measure used by most pearl dealers to communicate with pearl producers and wholesalers.

There is a special vocabulary used to describe the length of pearl necklace strands.

  • A collar is 25 to 33 cm in length, sits directly against the throat and does not hang down the neck.
  • Pearl chokers are 35 to 41 cm in length and lay at the base of the neck.
  • One strand of Princess length is 43 to 48 cm in length and comes down to or just below the collarbone.
  • Matinee length measures 50 to 60 cm in length, falls just above the breasts.
  • Opera length is 70 to 90 cm in length and is long enough to reach to the breastbone or sternum of the wearer
  • Pearl rope measure more than 115 cm in length such are any lengths that fall down farther than an opera.

There are 3 different types of pearls: Natural, Cultured and Imitated Pearls.

Let’s start with the natural ones. The most valuable but rare pearls occur spontaneously in the wild. These pearls are referred to as natural pearls. All shelled mollusks can, by natural processes, produce a pearl when a microscopic object becomes trapped within the mantle folds. Pearls are formed inside the shell of certain mollusks as a defense mechanism against a potentially threatening irritant such as a parasite, or an attack from outside that injures the mantle tissue then the mollusk creates a pearl sac to seal off the irritation.

Freshwater pearls form in freshwater mussels, which live in lakes, rivers and ponds. Saltwater pearls grow within pearl oysters, which live in oceans and are usually cultivated in protected lagoons or volcanic atolls. Only one out of a hundred wild oysters or mussels has a pearl.

The Cultured pearls are formed in pearl farms with human intervention as well as the natural process. A tiny piece of mantle tissue, called a graft, from a donor shell is transplanted into another shell, causing a pearl sac to form into which the tissue precipitates calcium carbonate. After a bead is inserted into the oyster, it secretes a few layers of nacre (mother-of-pearl) around the bead; the resulting cultured pearl can then be harvested in as few as six months.

Imitated are widely sold as inexpensive jewelry but the poor quality of their iridescence and such makes them easily distinguishable. Most of them are made of nacre, glass, plastic or wax coated with a solution containing fish-scales. Although imitated pearls look the part, they do not have the same weight or smoothness of real pearls, and their luster will dim.

Pearls are unique, so when you look at each pearl on a necklace, the color, shape, size, and luster of the pearls are not exactly the same. Fake pearls usually have the same size and shape. True pearls do not have a particularly neat shape. Naturally grown pearls are very difficult to have a necklace all the same shapes, especially those that are rounded or pearls that is particularly uniform in size. Even when the weather is hot, true pearls have kind of cool to them while plastic beads generally feel warm. If the pearls are real, then a pearl powder will be produced when you rub them together but if the pearls are fake, they will have a slip or smooth surface.

Now you can safely go and choose a princess length of pearls knowing what you’re dealing with. I believe pearls are timeless and will always radiate a sense of elegance.

written by June Litman