Pearl Grading Factors

by Brad Kaufman, guest AAP blogger

(image cred: Shutterstock)

When buying a diamond, the conscientious consumer learns the 4Cs—cut, clarity, color, and carat weight. Created by the Gemological Institute of America (GIA) and the American Gem Society (AGS), the 4Cs give consumers and jewelers confidence in the quality of the diamond they purchase. A diamond with a certificate from either organization has a permanent grade and offers lasting proof of quality.

Much like for the diamond industry, the GIA has also established criteria for pearl grading. There are seven GIA factors that establish a pearl’s value. That said, many companies use their own, non-GIA grades. A lot of companies use the A-AA-AAA system that was popularized by the Mikimoto Company. The problem is, however, that they all don’t use the same standards of grading what constitutes an A quality as opposed to an AAA quality. Some jewelers even use an AAAAA quality. So while many might use the same A-AA-AAA grading system, one company’s definition of what classifies an AA pearl could be vastly different from another company’s A grade. In other words, while they might be using the same grading scale, not everyone used the same criteria for what defined a particular quality. While perhaps helpful in showing differences within their own stock, these scales do not distinguish the universal quality of the pearls.  At best they are somewhat informative; at worst, they are completely misleading.

At Add-A-Pearl, the GIA factors are carefully considered and used for the buying and selling of each pearl.  This allows Add-A-Pearl to procure the right quality pearls, ensure the continuity of the quality of the pearls being sold, and lets the costumer know what to expect when picking out their pearls.

Here are the seven factors Add-A-Pearl uses when assessing pearl value:

1. Luster: A highly valued factor, luster refers to the glowing appearance of a pearl or its ability to reflect light. Luster is defined by intensity and sharpness.  A pearl with a very high luster has an almost mirror-like appearance. Low quality pearls have a white, chalky appearance.
2. Shape: Throughout history, perfectly round pearls were always considered the finest and are going to be the most expensive due to their rarity. These days in some places, however, other shapes are also in high demand for their designer appeal. There has been a trend within designer jewelry as more designers are using non-traditional shapes, such as baroque and semi-baroque, to create eye catching and original pieces, but the perfectly round will be the highest in value and rarity.
3. Color: This factor is a combination of body color, orient, and overtone. The body color of the pearl is determined by hue, tone, and saturation.  Orient is the combination of colors glistening just below the surface of the pearl. Overtone is a layer of translucent color that appears over the pearl’s body color. Usually, creamy rose is considered the most desirable pearl color.  However, choosing pearls is a personal process and often reflects personal preferences when it comes to color appearance.
4. Surface: Surface quality refers to the condition of the skin of the pearl. Simply put, the fewer the visible spots or blemishes, the greater the value.  When considering blemishes, the number, size, location, visibility, and type of surface all play a role in determining the grade. Too many blemishes take away from the beauty of the pearl by adversely affecting the luster making the pearls not as pretty as they would otherwise be. It is virtually impossible to properly match blemished pearls.  The best grade of a pearl’s surface is “clean.”  These pearls are either blemish-free or only have very small imperfections.
5. Nacre Thickness: Essentially, it is nacre that makes a pearl a pearl, and nacre thickness is perhaps the most important aspect of the pearl that controls the beauty of the peal. Because without a nice thick layer of nacre on the pearl, all the other grading factors become secondary. It is secreted to cover whatever irritant finds its way into the oyster, clam, or mussel in question.  The nacre coating takes years to accumulate. Fine pearls have a longer maturation time and develop with thicker nacre. If the nucleus is visible, then the nacre is too thin. A chalky appearance may result from thin or poor layering of the nacre, lowering the luster grade.
6. Size: With all other factors being equal, a larger pearl will be valued higher than a smaller pearl. Cultured pearls are measured in millimeters rounded to the nearest half-millimeter.  Natural pearls are measured to the nearest tenth of a millimeter. Pearls value will increase exponentially with pearl size. For example, a 6mm pearl will not be twice as expensive as a 3mm pearl, it will be approximately 5 to 6 times the price. Keep in mind, the price goes up dramatically with each increase in mm size. Why, you might ask? It takes much longer to make a 6mm pearl than a 3mm pearl so you can expect fairly high price jumps when you start getting into pearls sizes over 6mm.
7. Matching: The pearls in a strand must have uniformity and consistency based on the other 6 factors to properly match each other. When it comes to matching, Add-A-Pearl is unsurpassed in the pearl industry. Time after time, year after year, our pearls match the pearls that preceded them to ensure a perfectly consistent and beautiful strand of pearls.

A commitment to these 7 factors is Add-A-Pearl's promise to provide necklaces that can be cherished and worn with pride.  Understanding these factors, each and every Add-A-Pearl owner will know their pearls are - and will always be - perfectly picked out to create a beautiful necklace tradition that will last for years.