Varieties of Pearls

The language of pearls can be confusing! Baroque pearls, mabe pearls - what are they? Are Tahitian pearls also South Sea pearls? If you find yourself baffled by the jargon, here's a look at the some common terms for different pearl varieties.

First, all genuine pearls fall into one of two categories - either Natural or Cultured.

Natural Pearls

Natural pearls are pearls that are harvested from oysters growing in the wild. Prior to the 20th century, all pearl jewelry was made from natural pearls. Nature rarely produces perfect rounded pearls of a size and shape suitable for jewelry, which is why most antique pearl jewelry commands such high prices.

Cultured Pearls

Pearls that are cultured were formed in oysters with a little human intervention, typically on pearl farms. This is done by "seeding" the pearl oysters by placing a nucleus - a tiny bead (known as a "shell bead") or a small piece of mantle tissue from a donor mollusk -in a certain place inside the shell. Pearls form around each around the nucleus. The oysters are cared for while the pearl grows, which can be several years. When they are large enough, the pearls are harvested. Some farm oysters produce several "crops" of pearls in their lifetime.

(For more information about cultured and natural pearls and how to tell the difference between them, see Natural vs Cultured Pearls.)

There are 4 different basic varieties of pearls, based on the type of mollusk which produces them:

South Sea Pearls

South sea pearls are produced by the South Sea Oyster - Pinctada maxima. This large species of oyster fittingly produces some of the largest cultured pearls to be found!

Unlike other oysters, where multiple pearls are grown in one animal, the south sea oyster can only have one bead implanted at a time. Fewer pearls are produced, leading to the higher cost of south sea pearl jewelry.

South sea pearls are highly desirable due to their satin-like luster. They are white, silver-white or golden in color.

Tahitian ("Black") Pearls

Tahitian pearls are produced by the black lipped oyster (Pinctada margaritifera) , found in the waters off Tahiti. The resulting pearls are not actually pure black, but are found in a variety of dark colors, ranging from silver-gray to charcoal or off-black, often with greenish, blueish or purplish overtones.

Akoya Pearls

Akoya pearls are cultured pearls grown in the Akoya oyster (Pinctada fucata). These are the classic cultured pearls - small, round pearls with a lovely luster, in white, cream or light pink. Akoya pearls are farmed mainly in China and Japan. Akoya pearls are very consistent in shape and easy to match, making them a favorite for pearl necklaces and bracelets.

Freshwater Pearls

The freshwater pearl, is produced by fresh water mussels instead of salt-water oysters.. Instead of using a bead to produce a pearl (the bead nucleated method), freshwater pearls are produced by inserting a graft of mantle tissue from another bivalve (mantle tissue method). Like natural pearls, freshwater pearls are made up completely of solid nacre and the shapes are somewhat irregular. Unlike oysters, which can only grow a couple of pearls at a time, mussels can grow as many as 40 pearls in one animal. Tons of pearls are produced annually, making Freshwater pearl jewelry is less expensive than other cultured pearls (such as the Akoya pearls). They come in a variety of colors, which are often enhanced by dying.

Finally, a few pearl varieties of note:

Mabe Pearls ("Blister Pearls")

Mabe pearls, also known as blister pearls, are pearls which develop on the inside of the shell, instead of in the body of the mollusk, resulting in an irregular half-spherical shape with a flat side. They come in a wide range of colors and the larger mabe pearls are most commonly used in pearl earrings and rings.

Baroque Pearls

The term baroque refers to any pearl with an irregular shape. Many natural pearls and freshwater pearls are baroque pearls.

Cortez Pearls

Cortez pearls are a form of "black" pearl found in black-lipped oysters and rainbow-lipped oysters, both found in the Gulf of California. Most of them are baroque pearls. Cortez pearls are known for their intense luster and variety of colors which, in addition to the "traditional" pearl colors, can include tones of blue, gold, green and violet.

Keshi Pearls

Keshi pearls are cultured pearls initiated by the bead nucleus method, where at some point the animal has expelled the bead nucleus. The resulting pearl is solid nacre. Keshi pearls are usually very small but have an impressively deep and beautiful luster.

Biwa Pearls

One of the first types of pearl to be cultured, Biwa Pearls (from the Biwa Pearl Mussel) were first farmed in Japan in 1914. They reached the height of their popularity in the early 1970's, when they were produced in such quantities that the Biwa Pearl Mussel became nearly extinct from overfarming! The industry was saved by crossing it with another type of freshwater mussel, however pollution has taken a toll on the Biwa pearl industry in recent years. Biwa pearls are irregular in shape, usually elongated, and exhitib good color and luster.

Colored Pearls

With the exception of the dark Tahitian and Cortez pearls, pearls are typically white to off-white, cream, pink, silver or golden in color. The exotic colors like pistaschio, green, peach, blue, apricot, peacock and lavender ? You may find some Fresh water, Tahitian or Cortez pearls in those shades, but a lot of the less expensive jewelry in these exotic colors uses pearls which have been color treated or processed.

Simulated "Faux" Pearls

Last but not least, we come to the simulated or faux pearls. They may have other labels like "synthetic" or "replica" or "crystal pearls", but the important thing to know is that all these words are just nice ways of saying "fake!" These are beads, manufactured to resemble actual pearls. Some of them may be very attractive and on the better pieces the manmade lustre may hold up quite well to wear, but they are imitations nonetheless.

Majorca pearls, Majorica pearls, Mallorca pearls and Shell pearls are also names given to certain imitation pearls. The first three are made in Majorca, Spain, and are considered to be some of the highest quality imitation pearls in the world. They are made by a process which involves dipping glass beads in an irridescent substance multiple times and polishing them in between. Shell pearls are created in a similar manner.

So how do you tell if a piece of pearl jewelry is the real thing? The old test of rubbing pearls against your teeth is pretty foolproof. Because they are composed of multiple layers of nacre, genuine pearls have a slightly "rough" or "gritty" feel to them which is hard to replicate. Imitation pearls will feel completely smooth.