About Japanese Akoya Cultured Pearl


About Japanese Akoya Pearls

    Then, in 1905, after 12 years of painstaking work and trial-and-error, he successfully produced his first totally round pearl. What had once been a gem reserved for the upper class and nobility, would now be available for all to own and cherish. In the 1920's, when Japanese cultured pearls were first introduced into the jewelry market, they confused pearl buyers, and raised much debate as to whether or not they were "real" pearls. But soon the world realized that cultured pearls were as real as natural ones, and that nature had simply been encouraged by human ingenuity. What Kokichi Mikimoto had helped create was an industry, one so closely associated with Japan today. The sea around the southern half of Japan is the largest habitat in the world for Akoya oysters.
    Here, over the past hundred years, Japanese pearl growers have refined the techniques of pearl cultivation to a high art -- to a point where some of the world's loveliest pearls are grown, in a country where attention to detail combines so well with the love of beauty. Today, some two thousand independent growers harvest pearls in the waters of Japan -- large and small cultivators alike, employing the same basic techniques to grow these lustrous gems to perfection.
    You learned how cultured pearls are generally cultivated, harvested and processed for market. Now let's see what points of interest apply in these areas to the Akoya pearl specifically. We'll do the same with South Sea and Tahitian pearls as well. Akoya Pearl Cultivation Akoya pearls take their name from the comparatively small Akoya oyster in which they form, also known by its scientific name Pinctada fucata. Most Akoya oysters used in pearl farming are bred in hatcheries, to ensure the safety of the species. Much research has gone into breeding hearty, healthy Akoya oysters -- to produce pearls so well-known for their superior luster and color. As with all cultured pearls, Akoya oysters are nucleated with a hard-shell bead and mantle tissue from an oyster that has produced a high-quality pearl in the past. But compared with the other species of saltwater cultured pearl oysters, many more Akoya oysters are nucleated.
    Generally, Akoya cultured pearls take 10 to 18 months from the time they are nucleated to the point they're ready for harvest. Akoya Pearl Harvesting Akoya cultured pearls are the most difficult and costly to grow because of the low survival rates of their host oysters. Less than 50 percent of Akoya oysters survive the nucleation process, and those that do go on to produce pearls can do so only once. Of all Akoya pearls produced, less than 5 percent are considered high quality. Nevertheless, the total number of Akoya pearls harvested every year generally exceeds other types of saltwater cultured pearls. This is why most cultured pearl necklaces are made of Akoya pearls.

Akoya Pearl Processing

    The exacting procedure of sorting cultured pearls is especially time-consuming with Akoya pearls. One reason is: there are so many pearls to sort through. Another is that Japanese matching requirements are generally stricter than those for other pearl types. In fact, Akoya cultured pearl producers seek nearly perfect matches among their pearls. Such high matching standards result in 90 percent of all Akoya pearls harvested to be lightly bleached and tinted after drilling. These color enhancements are intended to be permanent, and should not change over time.

Akoya Pearl Quality Evaluation

    It's generally accepted that Akoya pearls, the classic cultured pearls of Japan, are the most lustrous of all pearls. But "luster" is only one of the 5 quality factors used in judging cultured pearls, the others being "surface," "shape," "color" and "size." Let's review these quality factors, and see how each applies to Akoya pearls. A bit later, we'll do the same with South Sea pearls and Tahitian pearls.

Quality Factor One: Luster

    Luster is considered the most important quality factor in pearls. Luster refers both to a pearl's brilliance -- the way its surface reflects light -- and its inner glow: the way it refracts light. A pearl's luster is generally evaluated in terms of "high" to "low," with grades of "medium" in between.
    High-luster pearls are bright, and have a deep-seated glow. They reflect objects near them clearly. Though high-luster pearls usually have thick nacre coating, thick nacre doesn't always guarantee a pearl will have high luster. This is true because genetic imperfections in some oysters don't allow them to secrete nacre in perfect patterns that result in high luster. Low-luster pearls, on the other hand, have low reflective and refractive qualities. They may appear too white, or dull or chalky, and they usually have only marginal nacre thickness.

Luster of Akoya Pearls

    Many experts believe that Akoya pearls have the highest luster of all cultured pearls, and it has to do with their nacre coating. The Japanese waters in which Akoya pearls grow are considerably cooler -- 10 to 15 degrees cooler -- than those in warmer climates, where other types of saltwater cultured pearls are grown. The cooler conditions cause Akoya pearls to develop their nacre coating more slowly, and with a more compact crystal structure. This is what increases Akoya pearls' reflective and refractive qualities. Even though Akoya pearls' nacre coating is generally thinner than that of most other saltwater varieties -- about a half millimeter thick -- their luster shines the brightest.

Quality Factor Two: Surface

    Surface is the second most important quality factor in pearl evaluation. Surface quality refers to the amount and kinds of flaws that appear on the outside of a pearl. Surface is generally evaluated in terms of "clean" to "heavily blemished," with grades of blemishing in between. "Clean" pearls have virtually no spots, bumps, pits, cracks, circles or wrinkles on them. Such flaws, on the other hand, dominate "Heavily blemished" pearls. It's important to note the difference between "damaging" and "non-damaging" blemishes. Damaging blemishes are those that tend to become larger over time. "Cracks" and "chips," often near a pearl's drill holes, are damaging blemishes. Non-damaging blemishes do not worsen over time. Spots, bumps, pits, circles, and wrinkles are considered non-damaging blemishes.
    Generally, the cleaner the surface of a pearl, the more valuable it is. But it's very important to remember that, as products of nature, pearls are almost never flawless -- and imperfections, because they're natural, don't necessarily detract from the beauty or value of a pearl.

Surface of Akoya Pearls

    Akoya pearls are typically clean, generally free of heavy blemishes. This is a result of their comparatively short cultivation time, and the strict quality standards Japanese pearls are subject to.

Quality Factor Three: Shape

    Pearls are placed into eight basic shape categories: "round," "drop," "button" "oval," "semi-round," "circle -- or "ringed", "baroque," and "semi-baroque." Generally, the rounder the pearl, the more valuable it is. Perfectly round pearls are very rare. But though baroque pearls are often less costly, they can be just as lustrous and appealing as the round.

Shape of Akoya Pearls

    Akoya pearls are generally sold in the "round," "semi-round," "drop" and "baroque" shapes. They don't often appear as "buttons," "circles," or "ovals."

Quality Factor Four: Color

    Saltwater cultured pearls display a fascinating array of colors, the entire spectrum, in fact: from white to black, and virtually ever color in between. It's important to note that no color is considered superior to another, and, as always, preferences are entirely up to a customer's taste. Yet, as a general note when making suggestions: rosť and silver/white pearls tend to look best on fair skins, while cream and gold-toned pearls are more flattering to darker complexions.

Color of Akoya Pearls

    Akoya cultured pearls come in rose, silver/white, cream, gold, and blue/gray.

Quality Factor Five: Size

    The size of a pearl is measured in millimeters, through its diameter. Pearls can be smaller than 1 millimeter in size too as large as 20 millimeters and more. The average and most popular size sold today is 7 to 7-and-a-half millimeters. Though a pearl's size is not an indicator of its quality, it will determine its price. With all other quality factors being equal the larger the pearl, the more valuable it is. The reason is simple: it's just more difficult to grow a large high-quality pearl. Therefore, pearls that are 7 millimeters and larger will always command higher prices.

    Size of Akoya Pearls

      Akoya pearls range from 2 to 10 millimeters, with 7 millimeters being the average size.

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