Pearls are gems created by living creatures, natural and cultured pearls are composed of calcium carbonate in minute crystalline form, deposited in concentric layers. The gems grow within the shell of certain mollusks, usually oysters or mussels. Pearls can be identified by their luster, iridescence, and color.
However, a pearl’s value also depends on its size, shape, lack of surface flaws, symmetry as well as color. The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries. In this blog post, I will outline a practical pearl-buying guide.
Luster
This is sometimes referred to as the brilliance of a pearl. In simple terms, this is a pearl’s shine and glow. The higher and deeper the luster, the more valuable the pearl. Pearls with a high luster display strong and sharp light reflections and a good contrast between the bright and darker areas of the pearl.
Pearls with low luster look milky, chalky, and dull. As a buyer, you want to select pearls with a good luster.
Shape
Normally, the more round and symmetrical the pearl, the more costly it is. Nonetheless, unique, asymmetrical shapes are desirable and are used to create unique pearl pieces.
The lowest-priced shapes are baroque (irregular and asymmetrical in shape) or with ring-like formations encircling the pearl.
Surface Quality
The fewer and less obvious the surface flaws, the more valuable the pearl. For example, blemishes on single pearls (rings or earrings) tend to be more obvious and are less acceptable than those bunched up with others on strands (necklace or bracelet).
It’s normal for pearl strands to have blemishes; natural pearls normally have more flaws than cultured Akoya pearls. That’s because they’ve been in the gonads of the oyster longer and thus have had more time to develop blemishes. Also, cultured pearls from the South Seas are more likely to have flaws than Akoya pearls (which have a thinner nacre coating).
Color
Saltwater pearls that are yellowish usually sell for less than those that are white and light pink in color. For example, golden South Sea pearls cultured in Indonesia and the Philippines are an exception and can indeed sell for as much as white South Sea pearls. This is granted the golden hue is intense and natural.
Natural-colored “black pearls” (do not that these are actually gray) can sell for as much as white pearls of the same size and quality as long as they have overtone colors and are not just plain gray. The overtone colors are visible in the light-colored areas of black pearls, maybe green, pink, blue, or purple.
Pink overtones are desirable on white pearls and are visible in the dark areas of the pearl. On the other hand, greenish or yellowish overtones tend to reduce the price of white pearls. Sometimes, iridescent rainbow-like colors are visible on pearls. Pearl iridescence is always considered a valuable quality by gemologists.
How color affects the pricing of freshwater pearls varies from one dealer to another. Often it has little or no effect. However, when comparing the prices of any pearls, try to compare pearls of the same type and color.
Nacre Thickness
The issue of nacre thickness is actually dependent on the type of pearl. Nacre thickness is not a price factor for natural pearls because they’re nearly all nacre. However, it is of critical importance in cultured saltwater pearls.
A thicker coating of nacre on a cultured pearl increases its hardiness and thus durability. Before 1960, Japanese Akoya pearl farmers left the pearls in the oyster for at least two and a half years. Around 1979, pearl harvesting started to be done just after six to eight months. The result—a lot of inexpensive, thin-nacre pearls on the market, many of which look like dull white beads and have nacre that’s peeling off the pearls.
Fortunately, better pearls with thicker nacre are also available, but they’re rarely as thick as those cultured before the 1960s. This is a market secret known only to experts and unscrupulous sellers who might try to pass off thin-coated pearls as high quality.
South Sea pearls normally have a thicker nacre coating than Akoya pearls. Nacre thickness is one of the most important quality factors for cultured saltwater pearls because it affects both the beauty and durability of the pearls.
Nacre thickness is not as important a factor in cultured freshwater pearls as in saltwater pearls. This is because most freshwater pearls have no shell nucleus. When one is present, the nacre is usually thicker than in Akoya pearls. One of the biggest selling points of cultured freshwater pearls is that they usually have a higher percentage of pearl nacre than their saltwater counterparts.
Size
Generally speaking, as it is for most gems, the larger the pearl, the more it costs. An exception would be round pearls with a diameter of less than 7 millimeters. For this reason, round pearls measuring 2–2½ mm might sell for the same price or more than a 4–4½ mm strand (pearl measurements are generally rounded to the nearest half or whole millimeter). Finally, pricing by size is often dependent on availability and demand. Comparing prices from various websites, especially when buying online, is prudent.
Treatment Status
Dyed and irradiated pearls cost less than those of natural color. It is worth noting that irradiated pearls tend to cost more than dyed pearls. This is because the laborious process of irradiation is more costly and is, as such, generally reserved for higher-quality pearls. During the 1920s and 1930s, dyed black pearls were considered fashionable and sometimes sold for as much as white pearls of similar size and quality.
The Types of Pearls: Saltwater and Freshwater Pearls
Before you price a pearl, you should know, for example, if it’s saltwater (from the ocean, sea, gulf, or bay) or if it’s freshwater (from a river, lake, or pond).
Good saltwater pearls (e.g., South Sea and Japanese Akoya) can cost several times more than freshwater pearls of similar quality and size. A reason for this is that one mussel in a lake can produce as many as forty freshwater pearls in one harvest.
Conversely, an oyster in the sea typically produces one or sometimes two saltwater pearls at a time. In addition, most freshwater pearls are cultured in China, whereas universally known labor costs tend to be generally lower than in Japan, Australia, and Tahiti.
Generally speaking, natural pearls are more valuable than cultured pearls. Natural pearls are usually formed as the mollusk secretes layers of protective nacre (pronounced NAY-ker) around an irritant that accidentally enters the mollusk.
The irritant can be a minute snail, worm, crab, or a particle of shell, clay, or mud. Read this post exploring the theories of natural pearl formation.
As was previously mentioned, cultured pearls are formed around irritants that man intentionally introduces in a mollusk. The irritant may be a shell bead, another pearl, or tissue from an oyster or mussel (mollusks). The shape and size of the resulting pearls depend to a large degree on the shape and size of the implanted irritant.
A buyer should be aware that more than 99% of the pearls on the market today are cultured. Perhaps the highest percentage of natural pearls sold today are found in Europe and the Middle East. In Europe, “pearl” means “natural pearl.”
In the United States, the term “pearl” has come to mean “cultured pearl” because natural pearls are not normally sold in jewelry stores (either brick and mortar or online). If a pearl is natural, it’s usually called a natural pearl. According to the U.S. Federal Trade Commission (a regulatory body), however, pearls that are cultured are supposed to be preceded by the word “cultured.”
You may have come across some sellers using the term “abalone pearl.” This is a type of natural pearl that is found in New Zealand and off the west coast of North America. Although the abalone is a snail and not an oyster or mussel, the colorful nacreous gems it produces are considered to be pearls because they consist of many concentric layers of nacre. The shell of the abalone is also used for jewelry and carvings.
Colorful pearls also come from the rainbow-lipped oyster in the Sea of Cortez near the city of Guaymas, Mexico. These pearls are cultured by Columbia Gem House and are available in semi-round, drop, and round shapes.
Besides knowing whether a pearl is natural or cultured, one must also consider if the pearl is a whole pearl, blister, or three-quarter pearl.
Whole pearls are much more valued than blister pearls— those which grow attached to the inner surface of a mollusk shell and three-quarter pearls—whole pearls that have been ground or sawed on one side, usually to remove blemishes.
Mabe pearls are made from blister pearls by removing the interior, filling it with a paste, and covering it with a mother-of-pearl backing. These assembled pearls are usually lowly priced. As a buyer, you should know that Mabe pearls (assembled pearls) are less durable than non-assembled pearls.
Geographic Locations of pearl production
- Japan is still the major producer of Akoya pearls that are 7 mm and above in size (higher-priced pearls).
- China has become a large cultivator of smaller Akoya pearls. Vietnam also produces small Akoya pearls.
- China is the main producer of freshwater pearls. The United States and Japan also produce freshwater pearls.
- Australia is the principal producer of white South Sea pearls.
- Indonesia is the largest source of golden South Sea pearls. The Philippines also produces golden South Se pearls.
- Black pearls are cultured in Tahiti (also known as Tahitian pearls). The Cook Islands and Mexico also produce black pearls.
- Most Natural saltwater pearls are harvested in the Persian Gulf, Red Sea, and the Gulf region of Manaar (that is, between India and Sri Lanka). Repositories of natural freshwater pearls have been discovered in other places, such as rivers of the USA, Scotland, Ireland, France, Austria, and Germany, but these are not commercially viable.
Buyer Beware
- Dyed and irradiated pearls are not always disclosed by online sellers. For black and golden South Sea pearls that cost thousands of dollars, it’s a good idea to get a report from a respected lab stating there’s no evidence of artificial coloring, especially if the seller is not reputable. If you are willing to spend thousands of dollars on a family heirloom, it is worth having it appraised by a gemologist. Ask the right questions before your purchase. Keep an email trail of discussions with online sellers.
- Unfortunately, imitation pearls are occasionally sold as cultured pearls by sellers. For information about detecting fake (faux) and dyed pearls, consult this post about spotting fake and authentic pearls.
- Another common problem with pearls is nacre so thin that it peels off. This can be detected both with the naked eye and a 10-power magnifier. You can usually avoid getting thin-nacre pearls by selecting pearls that have a high, rich luster (the richer the luster, the thicker the nacre). To learn how to evaluate luster, have salespeople show you a variety of luster qualities from very high to very low.
“”The richer the luster, the thicker the nacre”
— Anisa : My Simple Memory Aid for Pearl Quality
Pearl care tips
Clean your pearls by wiping them with a soft, damp cloth after wearing them. Avoid ultrasonics, steam cleaners, detergents, bleaches, powdered cleansers, ammonia-based cleaners, and chemicals. Pearls are attacked by all acids, but it’s safe to use acetone on pearls to remove glue and stains. Put your pearls on after applying hair spray, cosmetics, and perfume. If you wear pearls often, have your jeweler check the strands at least once a year to determine if they need restringing. See this post for a complete guide to pearl care.
After this concise introduction to pearls, you may be interested in reading this buyer’s guide.
