A pearl is a hard, roundish object produced within the soft tissue (specifically the mantle) of a living shelled mollusk. Just like the shell of mollusks, a pearl is composed of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearls (baroque pearls) occur. Pearls are not stones but are regarded as gems because they’re attractive, relatively rare, and can be worn as jewelry. Instead of being faceted, they’re usually polished, carved, or drilled. Of all the gems produced by living organisms, pearls are best known and most highly valued.
Pearl Price Factors in a Nutshell
The following factors can affect the price of a pearl:
1) Luster
2) Pearl type (saltwater/freshwater, natural/ cultured, whole/ blister)
3) Thickness of the nacre (pearly substance secreted by mollusks)
4) Color
5) Shape
6) Size
7) Surface quality
8.) Treatment status (untreated or treated? Type of treatment)
1) PEARL LUSTER: Pearl brilliance; the shine and the glow of a pearl. The thinner and more numerous the layers in the pearl, the finer the luster. The iridescence that pearls display is caused by the overlapping of successive layers, which breaks up light falling on the surface.
The higher the 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. Select pearls that have a good luster.
2) PEARL TYPE: Before you price a pearl, you should know, for example, it it’s saltwater (from the oceans, sea, gulf or bay) or if it’s freshwater (from a river, lake or pond). The U.S. Federal Trade Commission requires that freshwater pearls are referred to as “freshwater cultured pearls” in commerce. Good saltwater pearls (e.g., South Sea and Japanese akoya) can cost several times more than freshwater pearls of similar quality and size. One of the reasons for this is that one mussel in a lake can produce as many as forty freshwater pearls in one harvest. An oyster in the sea typically produces one or sometimes two saltwater pearls at a time.
It should be noted, however, that some new strands of large round pink freshwater pearls are retailing for over $12,000.
Natural pearls are more valuable than cultured pearls. Natural pearls are usually formed as the mollusk secrets layers of protective nacre (pronounced NAY-ker) around an irritant that accidentally enters the mollusk. Natural pearls are nearly 100% calcium carbonate and conchiolin. The irritant can be a minute snail, worm, crab, or a particle of shell, clay or mud. Cultured pearls are formed around irritants that are intentionally introduced by human. The irritant may be a shell bead, another pearl or tissue from an oyster or mussel. The shape and size of the resulting pearls depends to a large degree on the shape and size of the implanted irritant. Cultured pearls are usually used in designing pearl necklace and other accessories for women. Natural pearls come in many shapes, with perfectly round ones being comparatively rare.
Over 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. If a pearl is natural, it’s usually called a natural pearl. According to the U.S. Federal Trade Commission, however, pearls that are cultured are supposed to be preceded by the word “cultured.”
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 offer a big look at a low price, but they’re not as durable as non-assembled pearls.
3) NACRE THICKNESS: 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.
The thicker the nacre coating of a pearl, the better and more durable the pearl. Before about 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 1960’s. 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 the cultured freshwater pearls as it is in saltwater pearls. This is because most saltwater 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 pearl is that they usually have a higher percentage of pearl nacre than their saltwater counterparts.
4) PEARL COLOR: Saltwater pearls that are yellowish usually sell for less than those which are white and light pink. Golden South Sea pearls from the Philippines and Indonesia are an exception and can sell for as much as white South Sea pearls, provided the gold color is intense and natural.
Natural-color black pearls (they’re 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, which are visible in the light-colored areas of black pearls, may be green, pink, blue or purple.
Pink overtones are desirable on white pearls and are visible in the dark areas of the pearl. Greenish or yellowish overtones tend to reduce the price of white pearls. Occasionally, iridescent rainbow-like colors are visible on pearls. Pearl iridescence is always considered a valuable quality.
The way in which 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.
5) PEARL SHAPE: Normally, the more round and symmetrical the pearl, the more it costs. Unique, asymmetrical shapes, however, are also desirable, and are used to create distinctive pearl pieces. The lowest priced shapes are baroque (irregular and asymmetrical in shape) or have ring-like formations encircling the pearl.
6) PEARL SIZE: The larger the pearl the more it costs. An exception would be round pearls with a diameter of less than 7 millimeters. A 2-2 ½ mm strand, for example, might sell for the same price or more than a 4- 4 ½ mm strand (pearl measurements are generally rounded to the nearest half or whole millimeter). Pricing often depends on availability and demand.
7) SURFACE QUALITY: The fewer and smaller the flaws, the more valuable the pearl. Blemishes on single pearls tend to be more obvious and less acceptable than those on strands. It’s normal for pearl strands to have some flaws.
Natural pearls normally have more flaws than cultured akoya pearls. That’s because they’ve been in the oyster longer and have more time to develop blemishes. Cultured pearls from the South Seas are also more likely to have flaws than akoya, which have a thinner nacre coating.
8.) PEARL TREATMENT STATUS: Dyed and irradiated pearls cost less than those of natural color. Irradiated pearls normally cost more than dyed pearls because the irradiation process is more costly and because the irradiation process is more costly and because it’s usually reserved for higher quality pearls.
During the 1920’s and 30’s, however, dyed black pearls were considered fashionable and sometimes sold for as much as white pearls of similar size and quality.
GEOGRAPHIC SOURCES: Japan is still the major producer of akoya pearls that are 7 mm and above in size. China has become a large producer of small akoya pearls. China is the main producer of freshwater pearls, but they’re also cultured in the United States and Japan. Australia is the principal producer of white South Sea pearls, whereas is the largest producer of golden South Sea pearls. A significant quantity of golden South Sea pearls are also produced in the Philippines. The majority of black pearls are cultured in Tahiti, but some are also produced in the Cook Islands and Mexico.
The highest percentage of natural saltwater pearls have been harvested in the Persian Gulf, the Red Sea and the Gulf of Manaar (between India and Sri Lanka). Natural freshwater pearls have been found in the rivers of the USA, Scotland, Ireland, France, Austria and Germany, but they’re no longer commercially important.
BEWARE: Dyed and irradiated pearls are not always disclosed. 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 you don’t know the seller. Imitation pearls are occasionally sold as cultured pearls.
A more common problem is pearls with nacre so thin 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 that have a high, rich luster. To learn how to evaluate luster, have salespeople show you a variety of luster qualities from very high to very low.
PEARL CARE TIPS: Clean pearls by wiping them with 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 about once a year to determine if they need restringing.
About our Guest Blogger:
Ms. Aires Clemente is a jewelry design and crafts hobbyist. She have a degree in Fine Arts at Tokyo University of the Arts, and taken some courses on Jewelry and Metalsmithing at RISD. She currently works for a multinational jewelery company in Kyoto. Aires blogs about art jewelry at this URL, http://www.artjoolree.com
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