An Introduction To Pearls
inDecember 19, 2007 - 10:23am
Does this sound like you? "I have a drawer full of very nice pearl necklaces. My problem is I'm terrified to list them lest I should violate any fraud laws. I have bought two books, read numerous articles, taken several to my jeweler who gave an opinion about a few of them and executed numerous "tooth" tests trying to be really sure about whether or not they are real." – ‘Does anyone else have this problem? I window-shopped on several different e-commerce sites, to see what is being offered, and I suspect I'm not the only one who is unsure about this subject.
Certainly, this individual is not the only one with a horde of vintage mystery beads that resemble pearls. After all, "pearls" seem to turn up at every yard sale and practically multiply in box lots at estate auctions. So how do you determine if you have found a treasure or just another strand of white beads?
There are actually a number of clues and one easy field test that every savvy jewelry shopper can apply to separate cultured pearls from faux pearls. Before learning how to test pearls, it helps to know about the various types of "pearls"; the ones you are most likely to encounter on a shopping expedition, and which one of these is a bona fide natural pearl.
What are Pearls?
In the strictest sense of the word, a pearl is a natural organic gem created inside an oyster when calcium carbonate (in the form of aragonite crystals) is secreted in response to the intrusion of a foreign object. Yes, the "Queen of Gems" is actually a pathological formation! A bit of sand or a parasitic worm enters the mollusk and in an effort to relieve itself of the irritation, the animal forms a cyst around the intruder and plasters it with layers of aragonite deposited in many tiny overlapping plates. This coating is known as nacre and the light interference caused by the tiny overlapping plates is called luster.
Pearls can be spherical, irregular (baroque), or blister (mabe) in shape. They occur naturally in pink, black, light cream, medium cream, dark cream, white, blue, gray, silver, gold and yellow. However, the majority of pearls are white, cream and a very pale pink. Other fancy colors are rare and unusual, especially in the U.S. The majority of colored pearls seen in today's marketplace are color treated by dying or irradiation.
A pearl formed in this manner is a Natural Pearl. And only pearls that result from irritants that occur naturally can be called pearls without any modifier such as "cultured" or "freshwater" or "imitation".
Natural pearls are extremely rare and valuable. As our oceans become more polluted, natural pearls become ever more scarce. For perspective, the value of a strand of natural pearls is equivalent to that of a strand of perfectly matched fine natural Burmese rubies of the same size.
While almost anyone can learn to tell the difference between faux pearls and natural or cultured pearls, the distinction between natural and cultured pearls takes much greater skill and training. In many cases, the only definitive way to determine if pearls are natural rather than cultured is to have them evaluated by X-ray. Gem laboratories such as the Gemological Institute of American offer pearl identification and evaluation services, including X-ray testing, but most jewelers do not have the equipment and expertise to perform such services.
Remember Madonna in her ‘eighties’ incarnation, dripping with strands of pearls? Well, like most "pearls" we shoppers are likely to find on the treasure trail, those huge white beads were faux or costume pearls. The vast majority of jewelry that has been produced over the centuries with "pearls" has actually been made with imitation pearls.
It is tempting to believe that the beautiful antique piece of jewelry just acquired must contain "real" pearls because it is, after all, antique. However, simulated pearls were first developed as early as 1675. The earliest imitation pearls were made of hollow spheres of thin glass coated on the inside with a special varnish made of fish scales, and filled with paraffin or wax. Today, beads made from plastic, glass and shell are coated with various substances to create a pearl-like appearance. The most popular coating is still made from a substance containing fish scales; which gives a lustrous, nacre like appearance. Marjorica pearls are considered to be the finest imitation pearls made today.
The production of cultured pearls is a more recent phenomenon, dating to the early twentieth century. About 1920, Mikimoto and Nishikawa, two Japanese men working independently, perfected a commercially viable method of cultured pearl production. The procedure consists of cutting a small piece of mantle (tissue) from a living pearl oyster, wrapping it around a mother-of-pearl bead and inserting it in to the living tissue of another oyster. The implanted oysters are placed in cages suspended from rafts in calm waters. The cultured pearls then grow in the same manner as a natural pearl, with layers of aragonite deposited on the bead, or nucleus. Pearls can be harvested after five to seven years of cultivation, but pearls with thicker nacre and deeper luster are produced by cultivation of about 12 years.
In a quality-cultured pearl, the nacre thickness should be at least 1/2mm, with the mother-of-pearl bead forming only 60% of the total "pearl". Even to the trained eye of a gemologist, high quality cultured pearls can be virtually indistinguishable from natural pearls (especially if set in a piece of jewelry). After experience handling pearls, most jewelers and jewelry sellers will be able to immediately identify lesser quality cultured pearls, as their thinner nacre coating sometimes allows the nucleus bead to be seen under magnification.
Freshwater pearls were first created about 1930 and are extremely popular today, and widely used by jewelry artisans. Simply put, freshwater pearls are a cultured pearl product formed in freshwater mussels in cages in freshwater lakes. The majority of freshwater pearl production occurs in Japan and China, with some more recent production occurring in the Southern United States.
The majority of freshwater pearls have traditionally been created by the nonnucleated method in which pearls are formed by the implanting of mantle tissue (without a bead) into a living mollusk. This creates a pearl that is almost entirely nacre and of varied, irregular shapes such as the "Rice Krispies" of the early 1980s. Recently, implanted beads like those used in saltwater pearls, but in a variety of shapes such as potato, coin, rice, and even the spheres we associate with traditional cultured saltwater pearls have been used with greater frequency. Indeed, some of the most recently produced Chinese freshwater pearls are visually near duplicates of the Japanese saltwater pearls of the mid-century. The final freshwater pearl product can have a very small nucleus relative to the final size, resulting in a deeply luminescent appearance. Freshwater pearls occur in colors similar to those of saltwater natural and cultured pearls. However, in recent years, pearls in every color of the rainbow have been introduced. The “new” colors are achieved by using a variety of color treatments.
How can I tell these beads apart?
In judging pearl-like beads, use your senses!
Start with Visual Clues:
Move on to Tactile Clues:
Finish with the TEETH!:
Why does this work? Remember those overlapping plates of aragonite? They create a microscopically irregular surface that causes this feeling.
If you have ever tried this test and still felt unsure of the results, you were likely testing simulated pearls.
The best way to "learn" the feel you are after is to try it with a pearl or strand of pearls that you know to be cultured or natural. No, we are not advising you to head to your local jeweler and start gumming her merchandise. However, if you already own pearls or have a friend or relative who would be gracious enough to let you try the test, go for it!
Once you experience the feel of a pearl against your tooth, you won't easily forget it.
And if you are at a garage sale and don't want to stick someone else's old jewelry in your mouth? Do what lots of us do, risk the asking price, take your beads home and gently clean them with a soft cloth dipped in warm soapy water. Then try the test in the privacy of your own home. Whatever you do, resist the urge to scrub the pearls down with those wonderful new antibacterial wipes. Pearls are an organic substance and must be treated with gentle care to insure their survival.
Okay, I have cultured pearls! How should I describe them for sale?
As with all jewelry, remember that when selling pearls, you must always reveal the true nature of the material for sale. If you are confident that your pearls are cultured, then you may call them Cultured Pearls in your title and text description. You should not simply call them Pearls unless you have had them x-rayed and know them to be natural pearls. Nor should you call them "pearls", in quotations, as this can create unnecessary confusion for the shopper.
If you are unsure about the nature of your beads after applying all of the suggestions in the preceding paragraphs, then you may want to refrain from offering them in your e-commerce shop until you have them professionally appraised.
If your pearls are color treated, you must include this information in your title and text. And if they are freshwater pearls, they must also be described as such in both your title and text. If your pearls are imitation, you must describe them as simulated, imitation or artificial pearls in both your title and text.
The FTC has posted a page on the Internet to guide both the consumer and those engaged in the retail sale of jewelry concerning advertisements and the necessary disclosures. A link to this page is provided here:
Remember that these rules apply to those who sell vintage, antique and estate jewelry, as well as jewelry artisans in addition to other members of the retail and wholesale jewelry trades.