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Pearl Savvy (Frequently Asked Questions)

Pearls Have Always Been Prized

Just think how amazing it must have been to open an oyster shell and find a beautiful pearl, fully formed. Pearls have been prized by kings, queens and princes of many nations. They were once considered mysterious and thought to provide mythical powers to the wearers.

Pearls Are Gems

Pearls are considered organic gems, since they come from living organisms. They come from mollusks living in either freshwater (mussels in rivers/streams) or saltwater (oysters in oceans). Not all mollusks produce pearls.

How Are Pearls Formed?

Pearls don't just happen automatically. They are produced by a mollusk only in reaction to a stimulus. When a mollusk reacts to a grain of sand or a microorganism that gets inside its shell, it starts to cover the intrusion with a secretion called nacre. A pearl is the result of the depositing of many layers of nacre around this irritant.

It can take years to create pearls. The quality and size of the pearls depend, in large part, on the type of mollusk, water conditions and temperature, food sources available and growing time. These factors will also affect the price of the pearls.

What's the Difference Between Natural and Cultured Pearls?

When a pearl is formed on its own, we call this a natural pearl. Natural pearls are very rare today. Most of these are sold at auction and in estate jewelry.

When pearls are made with human intervention (by inserting a bead nucleus or a piece of tissue that will then be covered with nacre inside the mollusk's mantle organ), we call this a cultured pearl.

Most pearls on the market today are cultured pearls. They come in all shapes and sizes. Some have very famous brand names—like Mikimoto—named after the man who created the first viable pearl culturing company in Japan.

Different Mollusks, Different Pearls

Mollusks come in different shapes and sizes, too, and that's what helps create their own special pearls. It stands to reason that the bigger the oyster or mussel, the bigger the pearl can be.

The most important ones are:


—the Pinctada fucata oyster produces what we generally think of as the classic cultured pearl—round, white, lustrous spheres ranging in size from 2-9mm, with the average pearl between 6-7mm. Akoyas are found in the saltwater culturing of Japan and China, and have a glossy, mirror-like luster.


—the Pinctada margaritifera is a black-lipped oyster that is very large in size, therefore producing larger pearls. Tahitian pearls range in size from 8-14mm, averaging 9.5mm. These oysters naturally produce pearls with a more metallic luster and in beautiful colors—greys, greens, purples and blues—all of which we call black. Go figure.

South Seas

—A huge oyster called the Pinctada maxima is responsible for these cultured pearls—primarily in white, silver and yellow—called goldens. There are silver- and gold-lipped oysters and, you guessed it, they produce pearls of different colors. These pearls can be from 10-15mm, with the average pearl about 13mm. South Sea pearls generally have a soft, satiny luster.

Freshwater Pearls

—Today most freshwater pearls come from China and are cultured in mussels. The quality of freshwater pearls has improved greatly over the years and it is the increasing production—both in quantity and variety—that is responsible for the greater affordability of pearls today.

Freshwater pearls are usually from 4-11mm in size and generally display more orient than other pearls. What's orient? It's the rainbow-like, shimmery look just on or below the pearl's surface. Just like oil in a puddle. Orient is more likely on irregular-shaped pearls, like baroques.

Other Pearl Info to Know


—Technically not a pearl, but a by-product of the culturing process, I like to think of keshi as 'happy accidents.' These occur randomly and either look like teeny pearls ("keshi" means "poppyseed" in Japanese) or bits and pieces. Keshi have extremely high luster and lack a nucleus.


—Mabe pearls are grown by gluing a plastic hemisphere on the inside of the shell of a mollusk—in its mother-of-pearl lining—as opposed to inside the mollusk's body. Once the nucleus is covered by an adequate amount of nacre, the pearl is cut from the shell. The bead is taken out and the cavity is filled with epoxy resin and backed with a mother-of-pearl plate. Mabe pearls are considered blister pearls when in the shell.


—All mollusks that can form pearls also create an iridescent lining in their shells. This lining is called mother-of-pearl. This is the made from the same secretion—nacre—that is used to create the pearl.

Remember, all of the extraordinary pearls from these mollusks are cultured pearls because they are created with human intervention.

Shopping For Pearls

The Key Value Factors That Affect Quality and Pricing

When looking at pearls, the following factors are considered the most important: size (measured in millimeters), shape, color, luster, surface quality, nacre thickness and matching of pearls one with another.

All these factors, plus how long and difficult it is to culture certain kinds of pearls, affect the price of the pearls. Currently, there is no accepted universal standard of grading to help determine the relative value of pearls, so valuation is fairly subjective.

Faux or Real?

The old adage "You get what you pay for" is true, in most cases. But today, some brands of faux (French for "false") pearls can sell for as much or more than real pearls—depending on the type and size of pearl. Faux doesn't necessarily mean cheaper!

The most beautiful of the faux pearls—completely man-made—are the Majorica pearls, made in Spain. They are stunning, and expensive, but they are not made by mollusk—so they are not real pearls.

In general, a real pearl feels a little gritty due to the structure of its cells. If what you are feeling is exceptionally smooth, it may not be real. If it is both extremely smooth and perfect, it is even less likely to be real.

Real cultured pearls that are very smooth and perfectly round will be very, very pricy, again depending upon the size and type of pearl.

Color—Is It Natural, Dyed or Treated???

There is actually a dazzling array of natural pearl colors—whites, silvers, pinks, peaches, blacks, goldens, even blues and greens. Pearls are described by body color, overtones and hues.

It's important to know that many pearls on the market are now dyed or irradiated to produce "fashion" colors. This is not bad—but the treatment should be disclosed.

It is an also an accepted practice in the industry to bleach or polish as part of their processing for market, just like the drilling of pearls is necessary to make a strand. This is more often the case for freshwater pearls than for others.

Shape—How Much Fun is This??

Today, pearls come in all shapes, some naturally developed, and some based on the nucleus or tissue implanted during the culturing process. There are pearls that are round, off-round, oval, teardrop, and baroque. Pearls can be symmetrical or not. They can be shaped like sticks, Buddhas, or animals or have natural circular markings. And on and on.

The Beauty of Today's Pearl Market

So, you have to decide whether you want perfect or you want real, and at what price.

Then, you get the fun of choosing from a panoply of pearls—just an amazing breadth of real, cultured pearls used in all kinds of ways—to your utter delight. And best of all, there are pearls in all price ranges. It pays to look for what you want.

I'm here to help. Email me at

Susan Shieldkret is a GIA Pearls Graduate. She's been fascinated by pearls from an early age and has worked with them professionally since 2005.

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