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A fine pearl has a beauty akin to moonlight or mist, an ephemeral quality that seems impossible for a solid object to hold. Civilizations value these gems for their mesmerizing, dreamlike essence, which has inspired symbolism and lore across cultures. As the traditional June birthstone and a popular gift for any occasion, pearls have become a wardrobe staple.
However, this popularity hides a well-kept secret. With only handfuls of natural pearls collected each year, their extreme rarity pushes the prices of these gems ever higher. Fortunately for those on a budget, their cultured equivalents are abundant and available at a wide range of prices. Nevertheless, even purchasing a simple pearl necklace requires understanding pearl quality. The amount of information available can easily overwhelm a first-time buyer. To cut through the confusion, read the following brief beginner’s guide to pearl buying before getting into quality factors for pearl connoisseurs.
A Beginner’s Guide to Pearls
First and foremost, always purchase from a trusted jeweler with a good return policy, and remember: buy what you like! With the cultured pearl industry’s innovations, you’ve never had so many pearl jewelry choices.
Color and Style
Nowadays, pearl jewelry comes in all shapes, sizes, and colors to suit classic and modern tastes. Consider your wardrobe and skin tone when deciding on pearl color and style.
While pearls occur in all colors, traditional white ranks as the most popular and expensive. With a wide variety of treatments, pearls can be well matched in any color. However, some treatments may fade with time or wear.
If you’re shopping for a necklace, keep in mind the different lengths available for fitting with different pieces of your wardrobe.
When you have a good idea about color and necklace length, consider the size of pearls that you want. Traditionally, larger pearls are worn by older women, and larger sizes are more expensive. Due to current fashion trends, the price of Akoya pearls jumps at 8 mm. You’ll find sizes above this considerably more expensive.
Shape also has a significant effect on cost. Perfectly round pearls are the most highly sought and will fetch a premium price. Off-round or oval shapes will be less expensive and can still have the look of the traditional pearl necklace. You’ll find baroque shapes more highly discounted, plus their beautiful uniqueness is growing popular.
When pearl buying, look for high luster. The pearls should be reflective, not dull. This plays a key role in pearl quality and cost. However, determining luster is difficult before you actually see the pearls in person.
In addition, check for simpatico. Place the strand against your inner forearm to see how it looks against your skin. Choose a compatible tone.
Treatments and Care
Always ask your jeweler about any treatments your pearls may have. In particular, learn how they may impact their care. Get recommendations for cleaning and storage, too.
An Advanced Guide to Pearl Buying
Now that you know some basics, let’s explore pearl qualities in more detail.
Natural vs. Cultured Pearls
The main factor in the price of pearls is whether they’re natural. Cultured freshwater and saltwater pearls comprise most of the modern pearl market. They’re the equivalent of synthetic gemstones. If you’re considering buying natural pearls, obtain a laboratory report with an x-ray of the pearl.
At auction in 2015, a natural pearl and diamond necklace formerly owned by the Queen of Sweden and Norway, Joséphine de Beauharnais, sold for over 3.4 million USD. On the other hand, a similar necklace of cultured pearls without provenance may cost only a few hundred. The pearls are off-round and exhibit a variety of hues. In contrast, the expectations for a cultured strand of pearls stand much higher. These pearls should be well-matched and have greater symmetry.
Natural pearl necklaces without provenance can still sell in the six-figure range.
For those interested in investing, natural pearls are clearly superior to cultured pearls. Unless the jewelry has historic or artistic value, cultured pearl jewelry will hold little resale value. Natural pearls, on the other hand, are increasingly rare because of overfishing and pollution. Currently, these gems do very well at auction, often selling for many times the estimated amount. Investors should always take care to sell at a favorable time. In the 1990s, natural pearls sold for ten times less than some large, cultured specimens.
Evaluating pearl color can pose more challenges than most other gems. Pearls have a body color surrounded by a single-hued overtone or an iridescent orient. Illuminating the pearl with a bright light will disentangle these two qualities.
The most highly valued pearl body color is white. Akoya pearls, freshwater pearls, and South Sea pearls can have white body colors.
Tahitian black pearls naturally have a grey to black body color.
Strands of golden, pink, purple, blue, and red pearls are available but less common.
Often, matched colored strands contain dyed pearls.
Green-tinted white pearls are undesirable because they look unflattering against skin.
Overtone and Orient
In addition to body color, pearls have either an overtone or an orient. These seem to exist in a floating layer surrounding the pearl.
When a pearl shows large patches of a single color, this is its overtone. Pink overtones on a white body color rank as the most highly desired and expensive. Still, ivory and silvery white overtones also make popular options.
Some pearls show orient, a multi-colored or rainbow iridescence. Both effects occur because of light diffraction through layers of nacre, but rarely occur together.
Prized and Rare Colors
Akoya pearls with a white body color and rose overtone are the most popular and expensive of common pearl colors. Silver and ivory overtones are common and less expensive, while blue Akoyas are rare and highly prized.
Currently, golden South Sea pearls are popular but rare. Jewelers often create necklaces of golden pearls with treated specimens. Naturally golden pearls will fetch a good price.
For Tahitian black pearls, flywing (green) or peacock (green and pink) overtones are common. Overtones of blue, pink, silver, or copper are also widely available. Recent trends in Tahitian pearls include “chocolate” and “pistachio” tones. While treated chocolate and pistachio pearls exhibit intense colors and match easily, rare natural specimens with these tones garner considerable attention.
The finest pearls have a very high luster and reflect light well. These gems can even reflect readable text! Most commercially available pearls won’t exhibit such high luster. However, higher-grade pearls will sharply reflect a light shone directly on them. Lower grades reflect less crisply.
Fine Akoya pearls tend to have excellent luster, but South Sea and Tahitian pearls are less reflective. Increasing temperatures play a part in this. Akoya pearls grown in cold waters have thin layers of nacre, which reflect light well. Since pearls grown in warmer waters have thicker layers of nacre, they reflect less but display a lovely silky texture.
Video © Pearls of Joy. Used with permission.
Thinner layers of nacre also create greater translucency. Sometimes described as a “pearl of the finest water,” a highly translucent pearl is a sight to behold. Natural pearls and freshwater pearls seeded with tissue tend to have the greatest translucency. On the other hand, large, opaque beads used in most cultured pearls often comprise about 90% of the volume. This inhibits light diffraction through the pearl.
Nacre Thickness in Cultured Pearls
In cultured pearls, nacre thickness has a significant impact on the pearl’s quality.
Pearls with thin nacre will have less translucency and less iridescence. If poorly covered, an opaque nucleus can show through thin nacre and give the pearl a browned or muddied appearance. In addition, since nacre can wear down over time, the pearl won’t last as long. Examiners can measure nacre thickness through a drill hole or in x-ray images.
Shape and Symmetry
Pearls can grow in any shape, but the roundest pearls are the most highly prized. After luster, shape plays the next largest factor in a pearl’s quality. Slightly off-round pearls will fetch a lower price than well-rounded pearls.
Oval-shaped pearls can also make a lovely pearl necklace.
Baroque (or asymmetrical) pearls create a more unique look.
Teardrop pearls commonly find use in pendants and earrings, while button pearls, with round domes and flat backs, make lovely rings.
Pearl Shape Trends
Recently, baroque pearls with certain shapes have gained popularity.
“Fire ball” pearls are cultured with round seeds. Its nacre forms around the ball and outward in a line. When these have a metallic orient, they appear to be balls of reflective fire that dance as they move.
Once rejects, “ripple pearls” were meant to be round. Instead, the mollusk formed a wrinkled texture on the pearl, creating an interesting surface for color and light.
Perhaps the most spectacular, ringed “circle pearls” make eye-catching iridescence even more dramatic.
Some jewelry makers carve pearls with a design or to turn it into an attractive shape. Occasionally, a cultured pearl is seeded with a stone, and outer layers are carved so that the bright gem underneath shows through.
While carving may make some pearl connoisseurs cringe, the results are undeniably mesmerizing.
Texture, Surface, or “Skin”
A pearl’s surface is akin to a person’s skin. Blemishes, dimples, and bumps detract from a pearl’s beauty. When jewelers can’t hide these surface imperfections, the pearl’s price will lower. However, if a jewelry setting successfully hides a pearl’s blemishes, the pearl will “face up” nicely. Imperfections like these won’t dramatically lower the price.
On the other hand, bumps and dimples in baroque pearls add to the pearl’s character. These have less impact on price.
Although size doesn’t affect quality, a pearl’s size does influence its cost. Rarer, larger pearls will fetch a good price. Still, the range of sizes available depends on the type of pearl.
Akoya pearls don’t grow as large as South Sea pearls.
Uncommon in any size, most natural pearls found today are quite small.
For pearl necklaces, size matters. The size of pearls have a significant effect on cost and aesthetic. Furthermore, traditionalists should consider whether the size is commensurate with the age of the wearer. Currently, the 8 mm size ranks as the most popular. Akoya pearl prices jump at this size.
Finding the perfect pearls for a necklace is no easy task. Jewelers match pearls for color, shape, and size. They also carefully choose the pearls’ order, so that two pearls next to one another don’t have visibly different colors. A poorly matched strand has noticeable differences in color between adjacent pearls.
Cultured pearl necklaces with rare colors can take years to assemble. A well-matched strand of natural pearls may take a lifetime. A well-matched strand of natural pearls is incredibly rare. Thus, most natural strands are only somewhat matched.
Multi-colored stands enjoy more leeway. These pearls should complement one another.
Regardless of the beauty of the pearls themselves, certain colors of pearl complement certain skin tones. This is called the simpatico. To check for simpatico, place the pearls against the skin of your inner forearm. Then, pick pearls that suit you.
In general, those with fair skin will prefer white pearls with rose or silver overtones. People with darker skin will prefer cream-colored, golden, or black pearls.
Cultured Pearl Types
Several types of cultured pearls exist.
Quality Factors for Different Cultured Pearls
|Quality Factor||Akoya||Freshwater||South Sea||Tahitian|
|Color||Typically white or cream-colored with white, ivory, or rose overtone.||Variety of colors, often bleached white. Excellent, often rainbow orient.||White to yellow or golden. Overtones are slight.||Body is grey to black. Overtones can be green (flywing), pink, blue, or green and pink (peacock). Purple overtones are rare.|
|Luster||Very good to excellent||Very good to excellent (often less translucent than Akoya)||Good to very good (often with a silky appearance)||Good to very good (often with a silky appearance)|
|Shape||Usually very round||Off-round to baroque||Round to baroque||Round to baroque|
|Size||2 mm-9 mm; 10-11 mm are rare||2 mm-15 mm; rare above 10 mm||Common 10-14 mm; rare above 16 mm||Common 8-10 mm; rare above 16 mm|
|Treatments||Often bleached. Can be irradiated to turn the body color black. “Pinked” to produce pink overtones. Dyed for other colors.||Often bleached. Can sometimes be irradiated to create black pearls and metallic orient.||Often bleached. Some golden pearls have been heat treated.
|Can be heat and pressure treated to produce well-matched brown pearls.|
|Jewelry uses||Easily matched, the most common choice for white pearl necklaces.||Round pearls can rival Akoya. Baroque often used for fanciful shapes,||Often used for graded necklaces or pendants due to their large size.||Often used for graded necklaces or pendants due to their large size|
|Overall Price||Price jumps at 8 mm size.||2-8 times less than Akoya for a matched necklace, depending on the size.||10 mm South Sea pearls are similar or slightly higher in price than 9.0-9.5 mm Akoya.||2-3 times less than white South Sea pearls. Prices rise more rapidly above 12 mm.|
Byproducts of the Cultured Pearl Industry
When dealing with nature, not everything goes as planned. This also holds true in the cultured pearl industry. Nevertheless, byproducts and accidents can still have beautiful results.
To allow a mollusk to accept larger seed pearls, pearl farmers sometimes implant a mud seed. As the mud slowly expands, it allows the mollusk to adjust to having a large foreign object. The mollusk treats the mud as it would any other irritation, coating it in nacre. As a result, an oddly shaped, large, hollow soufflé pearl forms.
These often exhibit beautiful iridescence due to the mud’s chemistry. Their hollow nature also makes them a lightweight jewelry option. Because pearls are often priced by weight, these are much less expensive than traditional baroque counterparts.
Sometimes, an oyster will reject a pearl nucleus but will still generate nacre in the irritated area. This results in a keshi pearl, a nucleus-free pearl. These exhibit high luster and translucency because of their lack of a nucleus. However, keshi pearls are generally small.
This byproduct of the cultured pearl industry is becoming rarer. Many pearl farms now x-ray their mollusks to ensure they accept the bead nucleus. This prevent keshi pearls from forming.
Pearls can be treated in many different ways. It’s important to understand how your pearls have been treated, and how treatments can affect the value and care of your gems.
Akoya and freshwater pearls are routinely bleached, either by sunlight or with a mild hydrogen peroxide solution. White South Sea pearls may also be bleached. This widely accepted practice is permanent. Bleached pearls don’t require extra care.
Pearls are porous and readily accept dyes. Silver nitrate will turn the pearls black. Other dyes can create pearls of any color. A jeweler can often detect dyes by looking through the drill hole, where the surface and cracks will have more concentrated color. Although chemical dyes will fade over time, they will create better matched strands and pairs at a more affordable price.
Radiation darkens the pearl to create a blue or grey color. In saltwater pearls, the seed implant darkens. A jeweler should be able to recognize this through a drill hole. On the other hand, in freshwater pearls, the nacre darkens. As a result, the irradiated pearl exhibits an iridescent, metallic sheen. Irradiation is permanent and shouldn’t affect the pearl’s care. However, this treatment does reduce the pearl’s price.
Depending on the temperature reached, heating affects pearls differently. Most commonly, Akoya, freshwater, and South Sea pearls undergo heat treatment to improve luster. Heat treatment of South Sea pearls at a higher temperature can produce a desirable golden color, which jewelers can detect using UV spectroscopy.
Additionally, Jack Lynch of Sea Hunt Pearls reported a strand of Tahitian pearls that underwent heat and pressure treatment to create a uniform chocolate color.
Some unscrupulous dealers coat pearls to enhance their luster. Reputable jewelers frown on this practice because the coating can peel from the pearl, leaving the owner with a low-luster pearl. Sometimes, the coating will also damage underlying nacre. Coated pearls will appear smooth under magnification, whereas uncoated pearls have a scaly texture.
Tumbling and Buffing
Routine buffing and polishing will improve a pearl’s appearance somewhat. However, tumbling pearls wears down the nacre. For pearls with thin nacre, this process is detrimental to quality. Chemical buffers temporarily improve a pearl’s luster, but the effect wears off and the process removes nacre. Sometimes, pearls are tumbled with beeswax. This will also temporarily improve luster but with less wear on the nacre.
Cracks, pits, and drill holes may be filled with epoxy or another substance that matches the pearl’s color and luster. This practice is especially common in natural pearls, which have such high value that even damaged specimens hold value.
“Pearl doctors” sometimes peel layers of nacre from natural pearls, either to find more lustrous layers below or to remove a damaged outer layer. This work requires careful expertise. Pearl experts can see evidence of “working” under magnification. Depending on the extent of this process, peeled pearls can have discounts of 25% or more.
Calcareous concretions such as conch, tridacna, melo, and scallop pearls can be quite lovely, but these aren’t true pearls. They lack nacre and form in different organisms.
Although “blister pearls” and mother of pearl are comprised of nacre, these are also not true pearls.
Glass beads can be treated to look like pearls, but their smoothness gives them away. When rubbed together, their texture is smooth, while real pearls will be somewhat gritty. Any jeweler will be able to identify imitation pearls.
With cultured freshwater pearls so inexpensive, there isn’t much reason to purchase glass beads.