Grading South Sea and Tahitian Pearls
While there is no internationally recognized number or letter system for pearl grading, there are best-grading practices that are accepted and recognized by all professional pearl dealers within the industry. Understanding grading attributes and quality characteristics of South Sea and Tahitian pearls is imperative to properly shop and compare.
Pearl Grades Are Combinations Of Many Different Value Factors
As pearls have many differing value factors such as shape, luster, size and surface quality combining together to produce a unique gem, grading pearls can become very difficult. Although it is possible to grade each value factor individually, most purveyors of this gem rely on a simple letter-grade system.
The grading assigned by a retailer or producer is specific only to that source. In other words, grades assigned by different companies are subjective to those companies and cannot be compared with grading from different sources.
Which System Is Correct? The AAA-A System Or The A-D System?
Confusion abounds regarding the use of the A-D system (the Tahitian System) or the AAA-A system, popularized by the late Kokichi Mikimoto. While some pearl dealers swear by one method, another seller may use the other. So which is correct? The answer is simple – they both are.
As there is no International mandated system for grading pearls, nor is there an absolute alphabetical system, both systems are used interchangeably. Their use is largely based on location, but even this is a general rule of thumb, by no means absolute.
Both Systems Are Correct
In the USA both systems are often used by different pearl companies, which is considered completely acceptable if the seller makes it known what system is being used, and has an accurate representation of the quantified qualities.
In producing countries such as French Polynesia and Australia the A-D system is nearly universally used by producers of Tahitian and South Sea pearls. However, when the pearls are auctioned in Hong Kong , these same producers utilize the AAA-A system when selling to wholesalers.
Courtesy of Cultured Tahitian Pearl Grading by PearlParadise.com
| A-D (Tahitian) Grading | AAA-A Grading | Grading Description and Criteria |
|---|---|---|
| Top Gem | Gem Grade | Flawless pearl with excellent luster Pearl exhibits no inclusions or imperfections prior to setting or drilling |
| A | AAA | Flawless on at least 90% of pearl’s surface Only 10% of pearl’s surface may exhibit slight, concentrated imperfections Only a single deep inclusion allowable Pearl should drill or set clean to virtually clean Luster is very high |
| A/B | AA+ | Flawless on at least 80% of pearl’s surface Only 20% of pearl’s surface may exhibit slight, concentrated imperfections Only one or two deep inclusions allowable Pearl should drill or set clean to nearly clean Luster is high to very high |
| B | AA | Flawless on at least 70% of pearl’s surface Only 30% of pearl?s surface may exhibit slight, concentrated imperfections Only one or two deep inclusions allowable Pearl should drill or set nearly clean Luster is high to very high |
| C | A+ | Flawless on at least 40% of pearl’s surface Up to 60% of pearl?s surface may exhibit slight, concentrated imperfections Deep inclusions are limited to 10% of pearl?s surface Luster is medium to very high |
| D | A | At least 60% of pearl’s surface will exhibit flaws Deep inclusions and/or white spots within inclusions on up to 20% of pearl?s surface Luster is poor to very high |
*Cultured Tahitian pearls that do not fall into a category above, or do not meet the minimum nacre depth requirements of 0.8 mm per radius, do not pass the mandatory examination of the Ministere de la Perliculture of Tahiti. Those pearls are refused for export and destroyed.
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