Thursday, September 21, 2006

Different Types of Pearls:- Saltwater Akoya Pearls & South Sea Tahitian Black, White & Yellow Pearls

Today when one mentions "pearls" many different images might come to mind. There are many types of pearls available today than ever before. They offer a variety of colors, shapes, and sizes, and a wide range in price. Depending upon that catches your fancy, you can spend under US$100, or over US$1,000,000!

There are simple pearls for the "sweet sixteen", there are romantic pearls to add magic to the wedding day, there are one-of-a-kind pearls for the creative individualist, there are "important" pearls to mark an important milestone. Like diamonds, rubies, emeralds and sapphires, there is a pearl for every age, every occasion, every personal style, and every budget.

With so many possibilities, just knowing where to begin can be overwhelming. But it doesn't have to be. The key is in knowing what types are available, how they compare to each other, and how to recognize quality differences.

The variety available today results from the use of different types of oysters, the physical environment in which they live, and varying cultivation techniques used by the producers. They are generally classified as saltwater cultured pearls or freshwater cultured pearls, and divided into the white category, which includes shades from pink-white to silver-white to creamy-white and yellow-white, and the fancy color category, the best known of which are the natural color black cultured pearls and the deep yellows and golden cultured pearls.


Saltwater Cultured Pearls - Japan Akoya Pearls

Cultured saltwater, or "sea" pearls, are grown today by pearl producing oysters in several parts of the world, including Australia, China, French Polynesia, Indonesia, Japan, Korea, and the Philippines. Among the best known are the Japanese Akoya Pearls - the classic round, white pearl.

In the 1950s, cultured pearls meant Japanese Akoya pearls, and Mikimoto owned most of the oyster beds - about 12,000,000 oysters accounting for about 75% of the world's supply of cultured pearls. Since the 1960s , however, the production of cultured pearls began to extend to other pearl farmers in Japan, and to other parts of the world.

While the basic pearl producing process is the same in a saltwater or freshwater mollusc, in the case of round cultured pearls there is one significant difference, its requires the insertion of round "bead" nucleus in additional to the piece of mantle tissue. Following the surgical implant of the nucleus, many will either reject the implant or die, of those remaining, more will die before harvest. Only 30% to 35% of the original group of oysters will actually produce a pearl. Only a very small fraction of the pearls produced will be fine quality.

Saltwater cultured pearls command higher prices than freshwater cultured pearls. As you can imagine, the costs and the risks involved in producing saltwater cultured pearls are much greater.

Price Factors
Japan's Akoya pearl is for most people the "pearl of pearls" magnificent, lustrous, round, and white! While the finest Japanese cultured pearls are very costly, especially in sizes over 8 millimeters, they are much more affordable than the larger and even costlier South Sea pearls. They rarely exceed 10 millimeters in diameter, and when they do, they command exceptionally high prices. In addition to Japan, China is now a major producer of Akoyas.


LUSTER AND ORIENT
Fine Akoyas can exhibit the most intense luster of any white round, saltwater cultured pearl. Look for pearls with high luster and avoid those with low luster, indicating thin nacre. When nacre is thick, you may also see the prized, soft iridescence we call "orient" as you turn the pearl, as you "orient" it. Buy the best quality you can afford; insist on a lustrous pearl, even if this means the shape may be slightly off or the surface somewhat spotted.


NACRE THICKNESS
The nacre coating is less thick on Akoya cultured pearls. Overall, it is thicker than most Chinese Akoyas, and very thick nacre can be found in the very finest cultured Japanese pearls. Nacre thickness generally averages less than 0.4 millimeter in very round pearls, the finest can measure 1.0 millimeter in thickness.


COLOR
Normally in the white family. The rarest is white with a surface blush of pink, cream shades are also pleasing, and can be very beautiful, those with a slight greenish overtone cost less but can be very lovely against certain complexions. Occasionally pearls occur in unusual colors including pink, blue, gold and gray. Japan does produce natural "black" pearl are smallar than those produced in French Polynesia, is also produced by the "black-lip" oyster and is similar in appearance.


SHAPE
Japanese Akoya pearls are typically more round than all other pearls, they are occur in many shapes including round, baroque, symetrical and asymmetrical. Baroque Akoya pearls are also very desirable and much more affordable than round especially in teardrop or other distinctive shapes showing strong iridescence.


SIZE
The range is 2 to 12 millimeters in diameter, although they rarely exceed 10 millimeters. The price jumps upward rapidly with each half-millimeter from 8 millimeters up. Production of Japanese pearls is shifting away from sizes under 6 millimeters, focusing on sizes from 6 to 8+ millimeters.

TREATMENTS
The finest receive only minimal routine processing, but some are subjected to excessive treatments including chemical bleaching, tumbling and dyeing.

Black Pearls - South Sea Tahitian Pearls

Black pearls are not necessarily black. More often than not they range from a light to very dark gray, but they may also look green, pink, lavender, blue or brown. The colors are not always natural. Some are the result of dyeing and irradiation processes.

You may see strands labeled "black pearls" that sell for a few hundred dollars. They are probably artificially colored Akoya pearls whose natural color was undesirable. Dealers of pearls from Tahiti and the other islands of French Polynesia are now marketing their pearls as Tahitian cultured pearls or Tahitian South Sea cultured pearls, these two terms imply that the pearls are not dyed and they do not suggest that the pearls have a black color. In Tahiti, "black pearl" can only refer to a dark-colored pearl of natural color from the black-lip oyster.

Natural-color black pearls can also be confused with natural-color "blue pearls". Unlike black pearls, whose color is an inherent characteristic of the pearl nacre, blue pearls derive their color form foreign contaminants in the nacre itself or between the nacre and the shell bead nucleus. Black pearls and "blue pearls" can look the same but because of the difference in the origin of their color, "blue pearls" are worth less.

Since there can be a great value diference between black pearls, "blue pearls" and artificially colored pearls even though they may look the same, consumers need to be concerned about buying blackpearls that are misrepresented. Some guidelines here are given on how to spot pearls that are not true black pearls.

Price Factors
Black pearls are priced according to their luster, color, shape, surface perfection, size and nacre thickness as follows:

LUSTER
The best way to learn the luster potential of a black pearl is to look at some black pearls ranging from very low to very high in luster. Black pearls can look almost metallic. Good luster is an essential ingredient for pearl beauty. Keep in mind that lighting can affect black pearls in the same way it does white pearls, so compare pearls under equivalent lighting conditions.
Low luster in black pearls is often correlated with thin nacre, as is the case with white pearls. But thin-nacre black pearls can have good luster and thick-nacre pearls may have low luster. Consequently, it is best to treat luster and nacre thickness as two separate value factors.

COLOR
Lighter colored black pearls have become very popular and so have multicolored necklaces. Overtone colors on black pearls are blue, gold, silver and a reddish purple called "aubergine".
It is easiest to see the overtone colors in black pearls when the lighting is diffused and at a distance from the pearl. Overtones may be present in a variety of combinations such as pink and green, and they are considered a plus factor.
There is no standardized system throughout the pearl industry for classifying or valuing the color of black pearls, and considering the complexity of it, there may never be, at any rate, you should select colors that you like more and that look good on you.

SHAPE
Round and semi-round shapes are the most expensive. Drop shapes are the next most expensive followed by button shapes which are flat on one side and rounded on the other. The more symmetrical these shapes are, the more their value.
Baroque shapes and circled pearls with ring-like formations around them are the least expensive. When you need to cut down on the price of a black pearl, shape is a good category to compromise on. In fact, baroque and circled pearls often make more interesting jewelry pieces than round pearls do.

SIZE
Black pearls generally range in size from about 9 to 18 mm with their average size tending to be between 9 to 11.5 mm. A 14 mm pearl which costs US$5,000, might cost US$10,000 if it were 15 mm and US$30,000 if it were 16mm.
At the retail level black pearls tend to be described and priced according to millimeter size. Weight may be used as an additional means of identifying them. This is the opposite of round diamonds where the price is based on the weight.
On the wholesale level, however, large lots of black pearls are sold according to their weight, which is measured in momme ( 1 momme=3.75 grams = 18.75 carats).

SURFACE PERFECTION
If you select pearl with partially flawless surfaces, you can have a clean-looking one for a lower price. Flaws can decrease the price of black pearls considerably, which is an advantage for consumers. A black pearl can often be mounted in a way that will hide imperfections when worn.

NACRE THICKNESS
The best thing you can do is to choose pearls with as high of a luster as possible and buy your pearls from jewelers who consider nacre thickness important. Usually the best way of determining the nacre thickness of a black pearl is with an x-ray.

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