Pearl Grading: Pearl Color Grades
Pearl Grading System
Pearl grading is very similar to the "4 C's" of diamond grading in that the pearl grading system takes into consideration several key categories of qualitative comparison analysis. The pearl grading system consists of five main categories:
3. Pearl Color Grading
Pearls come in a wide range of natural colors (hues) and shades (tones), but some pearls are dyed or irradiated to suit a specific fashion trend or requirement. Naturally occurring pearl colors include traditional white as well as fancy silver, cream, pink, lilac, silver and gold hues. Other exotic natural colors include black and greenish-black Tahitian pearls which come from the black-lipped oyster Pinctada margaritifera.
The GIA classifies 19 hue (color) names for pearls. Pearls that fall into one of these 19 hue categories are also plotted on a center axis to indicate their tone (darkness) from pure white to medium grey and solid black.
Pearl Bodycolor, Heart, & Orient
The pearl's "bodycolor" is its main color classification which is determined by the type of oyster or mollusk that produces the pearl. Certain types of oysters produce pearls within a specific color range (bodycolor). Other factors in pearl coloration include the conditions of the water (temperature, water quality, salinity, etc.) and the type of nucleus which is implanted to stimulate the pearl's creation.
Besides the body or exterior color, higher quality pearls reveal color overtones which reflect the pearlšs layering or "heart." A quality white pearl may have a light pink or silver overtone to it, giving the illusion of depth. Overtones are translucent colors which sometimes appear over the top of the pearl's main bodycolor, although some pearls have no overtones at all.
The term "orient" refers to the shimmering, iridescent colors which appear to move and glitter when the pearl is turned or rotated, similar to the effects of scintillation in gemstones. This 'orient' phenomenon is caused by the way in which light is reflected through the various thin layers of nacre which make up the pearl's surface.
Color selection or preference can be a matter of personal taste and is often decided on the basis of whether the pearl color suits the wearer's skin. Color preference can also be effected by cultural trends and biases. Historically, Americans have tended to prefer pearls with a pinkish tone, whereas Europeans have shown a preference towards white or cream colored pearls. Cream and gold colored pearls generally compliment olive or darker skin tones, while white and pink pearls are more suited to Caucasian and Asian skin tones. Current trends seem to favor fancy Tahitian colors that compliment trendy baroque shapes.
Akoya and Freshwater Pearl Colors
Naturally black Akoya (saltwater) or freshwater pearls do not exist in nature, and these fancy colors are artificially infused by treatments such as dying, or by subjecting the pearls to irradiation. Some bright gold south-sea pearls and Tahitian "chocolate pearls" are created using a bleaching process, combined with heating.
In the 1930s, freshwater pearls from Japan's Lake Biwa introduced a wide variety of new colors to the pearl market. These colors were previously unavailable in saltwater variety pearls. Chinese freshwater pearl farmers have continued this trend with a wide variety of fancy colored freshwater pearls.
Pearl Color Treatments & Enhancements
Some commercially available pearls are bleached, dyed or irradiated to obtain their color. Misidentifying so-called "black pearls" as true Tahitian Pearls, and not as "treated pearls" can be a deceptive marketing practice as only pearls from the Black Lip Oyster can be a natural black color.
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