June – PEARL

One of the oldest pearl legends involves Cleopatra, who during a feast one evening, bet Antony that she could devour the wealth of a nation in one meal. Antony sensed an easy victory and accepted the wager. The meal Cleopatra served was wonderfully extravagant and thought she indulged herself, Antony was confident that he had won the bet. His confidence did not last. Clever Cleopatra won the wager with the help of a pearl. The Egyptian queen broke a large and beautiful pearl from an earring she was wearing and crushed it into a pearly power which she stirred into her wine. She then drank the wine with its valuable contents. That pearl was estimated to be worth one million ounces of silver.

The pearl was one of the first gems to be valued by people. Fresh from the shell, a pearl could be worn and admired without any polishing or faceting. Because of its mysterious source, early civilizations attributed magical powers to this unique gem.

The most extraordinary of all natural pearls was the Hope Pearl. It’s the largest known natural pearl, weighing 3 oz. It resided in a private collection in the 1800s, capped with a crown of red enameled gold set with diamonds, rubies, and emeralds. It surfaced again in 1974, when it was offered for sale at $200,000.

The Greeks believed that pearls were the hardened tears of joy that the goddess of love shook from her eyes as she was born from the sea. According to Arab legend, pearls were formed when oysters were lured from the depths of the ocean by the beautiful moon and then swallowed moonlit dewdrops. The Ancient Chinese thought that these gems originated from the brains of dragons.

The scientific explanation for natural pearls is almost as mystifying as folklore. When an irritant lodges in the flesh of an oyster, mussel, or clam, a protective substance called "nacre" is produced. Over years, layer upon layer of shimmering nacre coats the intruder, creating a lustrous pearl. Natural pearls are relatively rare, so a process evolved in which a piece of shell or bead was placed inside a mollusk to stimulate the production of nacre. This results in a cultured pearl, which accounts for about 90 per cent of the pearl industry.

Beneath the surface of every pearl there is a world of myth, history, science and adventure. The beloved white Akoya, the durable and affordable Freshwater pearl, the exotic natural black Tahitians and the ultimate in luxury, White and Golden South Sea pearls all have their own unique histories that make them a treasure in their own right.

Appearance:

• Dull to sub-metallic luster
• Transparent to opaque
• Phenomena: none
3 basic types of Saltwater Cultured Pearls:


• Akoya Cultured Pearls

Akoya oysters – P. fucata – are the main oysters used for saltwater pearl culturing in Japan and China. Most akoya cultured pearls are white or cream, and have hints of pink or green. The akoya oyster is relatively small, so it doesn’t usually produce a cultured pearl larger than 9mm.


• Tahitian Cultured Pearls

Tahitian cultured pearls have only been on the market since the 1970s, but their appealing colors and beautiful luster have caused people to rethink their ideas about pearls. The black-lipped oyster - P. margaritifera- produces Tahitian cultured pearls in colors like eggplant purple, peacock green, metallic gray, and grayish blue. This oyster is native to French Polynesia and I farmed there and in the Cook Islands. It can grow as large as 12 in. in diameter, sometimes weighing 11lbs.


• South Sea Cultured Pearls

South Sea cultured pearls come from one of the world’s largest mollusks. P. maxima was originally fished off the coast of Australia for its beautiful shell lining. Manufacturers used the mother-of-pearl in these shells to make buttons and materials for decorative inlay work in furniture. While the shells were commercially important, pearls were only thought of as a pleasant surprise. One hundred years later, it’s the cultured pearls – some measuring 15mm and larger – that inspire us today.
Freshwater Cultured Pearls - Pearls have been found in mussels in lakes, ponds, and rivers in almost every country. Today, cultured pearl farmers in China produce the overwhelming majority of cultured freshwater pearls. Freshwater pearls are cultured in mussels belonging to the family Unionidae. In the US, the chief cultured pearl-producing mussel is the “washboard” – M. nervosa. Only a small percentage of all freshwater cultured pearls, are cultured in the US.

Value Factors

The seven factors that determine the pearl’s value are: Size, Shape, Color, Luster, Surface Quality, Nacre Quality, and Matching.

GIA’s Pearl Description System gives the jewelry industry a consistent language for describing and categorizing natural and cultured, saltwater and freshwater pearls.

Value Factor 1: Size

A pearl’s ultimate size can depend on several variables – the size and health of the mollusk that produced it, the size of the nucleus, and the amount of time the mollusk spent underwater adding layers of nacre to build the pearl. Spherical pearls can range from 2mm to more than 20 mm in diameter. Irregularly shaped pearls can sometimes reach an impressive 50mm. As with other gems, the larger the size of the pearl, the more valuable it is. The importance of a pearl’s size to his ultimate value depends on the pearl type. If a fine peral is larger than usual for its type, it will be worth more than smaller pearls of the same type, because of the rarity of this desirable quality. If a South Sea and an akoya cultured pearl are equal in other ways, large size will have more effect on the akoya cultured pearl’s value than it would on the South Sea cultured pearl’s value. That’s because large size is less common in akoya cultured pearls.

Value Factor 2: Shape


While round is perhaps the most familiar pearl shape, pearls come in a parade of surprising forms. Pearls can resemble tear drops, crosses, coins, and other recognizable shapes. There can also be pearls with irregular freeform shapes that defy easy description. There are seven standard pearl shapes recognized by pearl professionals: round, near-round, oval, button, drop, semi-baroque, and baroque.

GIA’s Pearl Description System divides these seven pearl shapes into three major categories – spherical, symmetrical, and baroque.

Although pearl shapes vary, each shape has qualities that help determine its value. No matter what its shape, if a pearl is well-shaped or symmetrical, it will be more valuable than one that is irregular. Generally speaking, round is the most valuable pearl shape because find quality round pearls are relatively rare. Collecting enough large round pearls of exceptionally high quality round pearls to assemble a fine strand might take years. Worldwide, people recognize the familiar choker of round, white akoyas as a fashion classic.

Value Factor 3: Color


A pearl’s color contains three basic components – hue, the colors first impression; tone, it’s lightness or darkness, and saturation, it’s strength or intensity. Pearl colors tend to be muted and frequently appear grayish or brownish. Pearl colors range from white to black in tone. Cultured pearls display a broad palette of subtle hues, ranging from warm hues like yellow, orange, and pink to cool ones like blue, green, and violet. A pearl can have 3 main characteristics: body color, overtone, and orient – iridescent, rainbow colors shimmering on or below a pearl’s surface. All pearls display body color, but not every pearl possesses overtone or orient. A cultured pearls body town can be purple, brown, blue, orange, pink or many other colors. Different pearl types might display similar colors. Overtone is one or more subtle, translucent colors that lie across a pearl’s surface. The body color still shows through the overtone as the pearl’s main body color; however, if overtone is present on a pearl, it’s always secondary to body color.

Value Factor 4: Luster


The true magic of a pearl lies in its luster. In fact, luster is the most important of all the value factors to the beauty of a pearl. Luster is more than just surface sheen. It is caused by light traveling down through translucent layers of nacre, and reflecting back to the eye from deep within the pearl. The effect is that of an inner glow from the heart of the gem. There are four categories of luster – Excellent, Good, Fair, Poor. Pearls with little luster are far less valuable than highly lustrous pearls.

Value Factor 5: Surface Quality
Cultured pearls are organic, so it isn’t surprising when they show surface characteristics. There are many types of surface characteristics in pearls such as: abrasion, bump, chip, crack, flat, gap, pit, scratch, spot, and wrinkle. Based on this, GIA’s Pearl Description System divides them into four classifications:

Clean – Pearls can be blemish-free or contain minute surface characteristics that are very difficult to see when examined by a trained observer.

Lightly Blemished – Pearls show minor surface irregularities when inspected by a trained observer.

Moderately Blemished – Pearls show noticeable irregularities when inspected by a trained observer.

Heavily Blemished – Pearls show obvious surface irregularities. Durability might be affected.

In an ideal world, all pearls would be spotless. In reality, a completely clean pearl is a rare treasure. Even the finest pearl can contain minor surface characteristics.

Value Factor 6: Nacre Quality
Nacre is the very essence of the pearl itself. If the nacre is too thin, the pearl might look dull or chalky, or the nucleus might be visible. Nacre quality and luster are closely related. While most lustrous pearls have acceptable nacre thickness, not all pearls with thick nacre will be equally lustrous. The translucence and arrangement of the nacre plates also comes into play. Nacre quality can be classified in three ways: Acceptable, Nucleus Visible, and Chalky Appearance.

Value Factor 7: Matching
Like snowflakes, no two pearls are exactly alike. Realistically, then, individual pearls in a piece of jewelry can’t be completely identical. Matched jewelry items can be rated as: Excellent, Good, and Fair. The “Good” and “Fair” classifications are based on the degree of variation among pearls in the jewelry piece.

Knowing the value factors will help you understand the limits and possibilities for each pearl type.

Cleaning Methods:

• Ultrasonic: Never
• Steamer: Never
• Warm soapy water: Generally safe, but avoid strong detergents and vigorous scrubbing as this may destroy the nacre causing your pearls to lose their shine.




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References

Gemological Institute of America, GIA Gem Reference Guide 1995, ISBN 0-87311-019-6

GIA. (n.d.). GIA Grading and Reports. Retrieved July 29, 2011, from Gemological Institute of America:
http://gia4cs.gia.edu/cm/grading-reports.htm

ICGA. (n.d.). All About Gems. Retrieved July 30, 2011, from International Colored Gemstone Association:
http://www.gemstone.org/index.php?option=com_content&view=section&layout=blog&id=1&Itemid=69

IGS. (n.d.). IGS Reference Library. Retrieved July 29, 2011, from Internatonal Gem Society:
http://www.gemsociety.org/info/info.htm