Pearl Quality Guide 101

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Pearl Quality Guide 101

Although there is no official quality grading system for pearls (like the "4Cs" for diamonds), there are several characteristics that affect pearl's quality and value which you should consider before making a purchase.


Shape in pearls is divided into three categories: spherical, symmetrical, and baroque. The rarest and most valuable is the spherical or round pearl; these are judged on their degree of "sphericity" or "roundness". While fine pearls that are perfectly round are extremely rare, the closer a pearl comes to being perfectly round, the more expensive it will be.

Pearls with shapes such as teardrop or pear-shape are symmetrical pearls, and are judged on proportioning, outline, and good symmetry; that is, whether they have a nice, pleasing and well-balanced shape. Any strand of pearls should be well matched for shape, and when worn give the appearance of uniformity. Terms such as semi-round and semi-baroque are also used.

These are terms applied to pearls that are "out of round" but not so much that are irregular shape is interesting, or distinctive. These cost much less than other shapes. Symmetrical pearls are less expensive than round pearls-although there are some exceptions-but much more expensive than baroque pearls, which are irregularly shaped pearls.


Pearls with a bright, intense luster sharply reflects nearby images, will have a good nacre thickness; pearls that look very dull or chalky probably have very thin nacre or poor quality nacre. Roll the pearls to view them from all sides to make sure the luster is uniform. Examine them under a light source such as fluorescent lamp, looking for reflections of the light off the surface, paying particular attention to the brightness or sharpness of the reflections. Avoid strong, direct light. If the available light is too strong, hold your hand over the pearls to shade them, and examine in the shadowed area.


This feature refers to the degree of surface perfection. Finer quality nacre is very smooth, and nearly blemish-free, however, most pearls have natural surface characteristics that serve to identify them and act as "mother nature's" fingerprints. The cleaner the surface, the higher luster produced and more valuable the pearls become.

Think of pearl surface as you would your own skin. Just as our own is rarely completely free of little perfections, so it is with the pearl. Surface perfection refers to the pearl's skin being free of such things as small blisters, pimples, spots, or cracks. Imperfections may also appear as dark spots, small indentations, welts or blisters, or surface bumps.

While occasional small blemishes are not very uncommon, if large or numerous they are unsightly. A pearl with sizeable or numerous blemishes may also be less durable. The cleaner the skin, the rarer and costlier. If drilled, the closer the blemish to the drill hole, the less it detracts from both appearance and value. Fine pearls have virtually no spots, bumps, pits, circles or wrinkles. High luster will often make tiny surface imperfections less visible and generally compensate for these small imperfections. Also, when the pearls are strung as a necklace or mounted on earrings, the mounting and drill holes can do much to detract from any flaws inherent in the pearl.

Examine in several types of light: while diffused light is normally best for comparing factors in pearls, when checking blemishes, an intense light may highlight certain types. When examining pearls for blemishes, it may be helpful to check them both diffused light and an intense bright light. Examine against a dark background: a light background is normally best for comparing most pearl characteristics, but when checking for blemishes, it is sometimes easier to spot them against a dark background. Examine while rolling: place the pearl or pearl strand on flat surface and roll it to be sure that you have examined all sides, and so that the light catches any blemish and highlights it.


Pearl color includes: the body color (the primary color - light, dark, or colored), the overtone color (a tint that appears super-imposed on the body color), and a rare component called orient (an iridescent, or rainbow of colors that generally is found on baroque pearls, or those with an irregular surface).
The most valuable pearls in the light body color group are pink, pink rose and white rose with a very high luster, and are well matched, and round, with a clean surface. The finest dark pearls are black with a metallic green overtone color. Pearls also come in pastel colors such as: pink, purple, yellow, golden, green, silver, and blue.

The most valuable overtone color in light pearls is rose, and in black pearls, green is most desirable. The color of the "mother-of-pearl" inside the shell determines the pearl color, depending on the species.

Women should select pearls according to their own skin color. Rose colored pearls generally look best on fair skin. Cream colored pearls look best on olive skin. Black and silver colored pearls complement most skin colors.


Three things determine the size of a cultured pearl: the size of the mother-of-pearl nucleus, the size of the oyster, and the thickness of the nacre. Size is an important value factor. Certain sizes that are in fashion demand, may command premium prices. Supply and demand are the over-riding factors. Round pearls are measured according to their diameter, while baroque pearls are measured by their length and width. Size is determined by diameter and expressed in millimeters, since pearls are sold by the millimeter.

Cultured pearls are sold by millimeter size (one millimeter approx equals 1/25 inch): their measurements indicates the diameter of round pearls, and the length and width if not round. The larger the pearl, the greater the cost. A 2mm cultured pearl is considered very small, whereas Akoya pearls over 8mm are considered very large; in South Sea pearls, an 8mm pearl is small, 13mm to 15mm is average, and over 16mm is very large. Large cultured pearls are rarer and more expensive.

In Akoya pearls there is a dramatic jump in the cost after 7.5mm. Pearl strands are sorted by size, with a specific millimeter range: Petite: 6mm and below; Classic: 6mm to 7.5mm; Most Popular: 7mm to 7.5mm; Outstanding: 8mm. A pearl's size does not necessarily indicate its quality, but it most certainly does affect its price. All things considered, the larger the pearl, the higher its value.

It is critical that the pearls in any strand or piece of jewelry be evenly matched in terms of their size, shape, color, luster and surface. Visible variations of these qualities not only affect the piece's beauty but its value as well. A pearl's value is also based on its availability. Saltwater cultured pearls generally command higher prices than Freshwater cultured pearls, since a seawater oyster can only produce one or two pearls at one time and a freshwater oyster can produce up to 50 pearls at one time. Fine, natural pearls obtain the highest prices, at least 10 times as the cultured ones.

While, again, there is no official quality grading system for pearls, the most prevalent grading system used by manufacturers of pearl jewelry is the grading scale of "A", "AA" and "AAA".

  •     "A" - off round shape, surface may have small marks or imperfections difficult to see unless the pearls are studied closely, fair luster.
  •     "AA" - mostly round in shape, clean to mostly clean surface without significant imperfections, good luster.
  •     "AAA" - all round to mostly round, surface of the pearl is nice and clean, excellent luster (mirror-like uniformity-matching from pearl to pearl).

Therefore you may see a notation of an "AA" or "AAA" in our descriptions. You will also see, within that description, a full explanation.

After you have decided the type, color, size and quality of pearls, think about your budget. It is time to shop around and find a perfect pearl necklace for your love one!


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