Pearls are among the oldest gems in the world, dating back hundreds of centuries, and have always been a symbol of beauty, and elegance. They aren’t mined from the Earth as other gemstones but actually produced by living organisms like mussels or oysters when an irritant gets inside their body. The oyster, to protect itself, secretes a crystalline fluid, known as nacre, that gets deposited layer by layer, finally producing a lustrous pearl.
Nowadays, you can find both natural and cultured pearls and if you’re planning on buying pearls, you might be somewhat confused. What you need to do is purchase from a reliable brand with clear details on how they grade pearls.
Pearl grading is the practice of assigning degrees of quality to a pearl but unfortunately, there’s no standardized grading system to evaluate pearls and every company and pearl producer uses its unique grading system. One vendor’s AAA pearl necklace is another’s AA or even A Grade, making the grading subjective.
Below, we provide you with an insider’s guide to grading pearls so you can have at least some level of understanding of value and price when purchasing pearls.
7 Value Factors in Pearl Grading
All types of pearls are generally graded along 7 distinct value factors which include:
Nacre Quality and Thickness
Nacre thickness might be the most important value factor for pearls as it’s the foundation upon which all other characteristics rest. Without thick and well-layered nacre, the pearl won’t look as appealing as other peals and it will not last as long over the years. Tahitians and South Sea pearls have incredibly thick nacre, often averaging around 2-4 mm thick around the bead nucleus inside.
Luster is also one of the leading value factors as a pearl without good luster looks like a plain bead. Luster is a unique glow that comes from within the pearl produced by the light entering the pearl and reflecting back at the observer through the nacre layers.
The quality of the luster is directly related to how even and smooth the nacre layers are. Luster measures how shiny and bright a pearl appears and many established jewelers use this term to measure the sharpness of objects reflected on the pearl’s surface. The sharper the edges of reflected light sources, the greater the luster quality.
Pearl Surface Quality
Another value factor is surface quality which measures how clean and free from blemishes a pearl appears. Many buyers will notice a certain degree of surface imperfections such as abrasions, spots, bumps, and wrinkles. Chips and gaps are usually the most serious surface quality issues which may lower the value of pearls as they can cause the gemstone to crack or peel.
The size of cultured pearls can be anywhere from 1.00 to 21.0 mm and larger. Size can contribute to increasing prices because larger pearls are harder to cultivate and take much longer to produce.
Perfectly round pearls are the most conventional of all pearls shapes, and the next most popular shapes are smooth drops, buttons, and baroque. The most important factor is that the pearls have evenly symmetrical shapes that can be easily used in jewelry styles, and remain pleasing to the eye.
Pearl Color & Overtone
This factor is about the strength of the pearl’s body colors and overtones. Certain overtones are rarer and more valuable than others. The value is greater when the colors and overtones are easily visible and saturated.
Matching is key when evaluating the quality of pearl earrings, bracelets, and sets. They should match in color, overtone, luster, shape, and size. Multi-colored strands should be matched according to these factors, while body color and overtones can be mixed.
A-AAA Pearl Grading Scale for Akoya and Freshwater Pearls
Pearl farmers and retailers have adopted the A-AAA Grading Scale, based on the above value factors, as a way to grade Akoya and freshwater pearls.
Value factors are weighed heavily towards luster, surface quality, and nacre thickness, with factors like color, size, shape, and matching accounting for a lesser percentage of a pearl’s total grade within the A-D/A-AAA grading system.
This system grades pearls on a scale from AAA to A, with AAA signifying the highest grade and finest pearls. Although this grading scale is mostly common to freshwater and Akoya pearls, it’s accepted by many jewelers who work with South Sea and Tahitian pearls too.
Pearls are one of the most timeless and fashionable pieces you can own. Whether you’re looking for a traditional pearl necklace or a stylish pair of pearl earrings, having a basic understanding of the grading system will help you choose and invest in the right kind of pearl jewelry.