Pearls are a beautiful and precious gem formed inside the shells of certain mollusks as a defense mechanism against irritants. They come in a variety of colors, shapes, sizes and grades. Pearl grade refers to the quality grading system used to classify natural and cultured pearls based on factors like luster, surface cleanliness, shape, size and more. Understanding the pearl grading system is important for determining the value and rarity of different pearls.
How are pearls graded?
There are a few well-established grading systems used around the world to evaluate and classify pearl quality. Some of the main ones are:
- AAA-A System – The most widely used grading system globally. Rates pearls from highest quality (AAA) to lowest (A).
- A-D System – Commonly used in the United States. Rates pearls from highest (A) to lowest (D).
- Gemological Institute of America (GIA) System – Provides an expert assessment of cultured pearls.
- Tahitian Pearl Grading System – Specialized system just for black Tahitian pearls.
While the specific grading scales and nomenclature varies, all major pearl grading systems evaluate the following criteria:
Luster
Luster refers to the brightness and sharpness of reflection on the pearl’s surface. High quality pearls will have a bright, intense luster while lower quality pearls will look dull. A sharp, mirrored surface luster is most desirable.
Surface Cleanliness
This judges the cleanliness and purity of the pearl’s surface. Higher grade pearls will be free from spots, blemishes, pits, grooves or other imperfections. Lower grade pearls will show increasing amounts of flaws and blemishes on the nacre surface.
Shape
Shape evaluates the roundness, symmetry and attractiveness of the overall pearl form. Perfectly round pearls are graded highest while irregular, asymmetric shapes are graded lower.
Size
Larger sized pearls in general receive higher grades. However, the pearl should still maintain good luster and surface cleanliness in larger sizes. Extremely small seed pearls are graded low.
Color
Whiter and brighter bodycolors are graded best, with bright white being the top color grade. Lower quality pearls will show increasing levels of overtones and color tints.
Nacre Quality
This judges the thickness, uniformity and quality of the nacre layers that compose the pearl interior. High quality pearls will have thick, smooth nacre throughout while low quality pearls have thin or uneven nacre.
Pearl Grades Explained
Now let’s take a closer look at each specific pearl grade and what it signifies:
AAA Quality
AAA represents the very finest top quality pearls. An AAA pearl will have a highly reflective luster, no blemishes or flaws, excellent symmetry and thickness of nacre, large size (minimum 9mm) and pure white color.
AAA quality represents less than 5% of all pearls harvested. These rare pearls are suitable to be made into premium jewelry and are very valuable.
AA Quality
AA is the second highest pearl grade. AA pearls have excellent luster, near perfect shape and surface, large size (minimum 7mm) and pure white color. The nacre thickness and symmetry will be outstanding.
Compared to AAA grade, they may show very minor surface flaws or subtle overtones under close inspection. But overall AA pearls have exceptional quality suitable for fine jewelry.
A Quality
Grade A pearls are of the high end of fine quality. They will display excellent luster, a clean surface with only minor blemishes, good symmetry and moderately thick nacre.
Size may be slightly smaller, in the 6-7mm range. Color may show slight warm or cream overtones but still appealing overall. A quality represents the top grade for most pearl jewelry uses.
B Quality
B grade pearls are medium quality but still suitable for jewelry. They will show slight flaws in luster, surface cleanliness, shape and color. The nacre quality is decent but not exceptional.
Size is commonly 5-6mm range. Subtle spotting, pits and grooves may be visible. Color shows obvious warm overtones. Overall attractive but not for top end jewelry.
C Quality
Grade C pearls are low-medium quality. Luster is modest at best, with significant flaws clearly visible on the surface. Shape and symmetry are fair to poor. Size is commonly under 5mm.
Nacre thickness is uneven or on the thin side. Color has dark cream to yellowish tints. These pearls are only suitable for costume or casual jewelry uses where imperfections aren’t as noticeable.
D Quality
D grade is the lowest pearl quality. These pearls have very poor luster with a dull chalky appearance. The surface is heavily blemished with multiple pits, grooves, spots and bumps visible. Nacre thickness is uneven and thin.
Shape is quite irregular and asymmetrical. Size is typically 3-4mm. Color has heavy yellowish or brownish overtones. Lowest prices but rarely used in jewelry.
Tahitian Pearl Grades
Tahitian pearls have their own specialized grading system since they are black in color. The Tahitian Pearl Grading system consists of the following categories:
- A Grade – Showing excellent luster, surface and size. Must be 8mm or larger.
- B Grade – Displaying good luster and surface with minor flaws. Size ranges 6.5-7.5mm.
- C Grade – Modest quality with noticeable flaws. Size around 5.5-6.5mm.
- D Grade – Lower quality with poor luster and blemishes. Under 5.5mm size.
Color is also highly important for black Tahitian pearls. The most valuable colors are a rich, intense black called Peacock Black. Dark charcoal grey bodycolors are lower value Pigeon Black shades.
Factors Influencing Pearl Grades
There are several variables that impact the overall quality grade a pearl receives. These include:
- Type of Pearl – Saltwater pearls usually achieve higher grades than freshwater.
- Pearl Culturing Method – wild pearls receive the top grades. Japanese Akoya and South Sea cultured pearls reach high grades more often than Chinese freshwater pearls.
- Mollusk Health – Healthier mollusks produce higher grade pearls on average.
- Growing Environment – Pristine warm, clean ocean waters lead to top grade pearls.
- Harvesting Time – Longer culture times allow for larger, higher grade pearls to form.
Understanding what goes into culturing a top grade pearl helps appreciate their value and rarity.
Value of Different Pearl Grades
As expected, higher pearl grades demand much higher prices and values. The value difference can be summarized as:
| Pearl Grade | Price Range |
|---|---|
| AAA | $300-$1500+ per pearl |
| AA | $150-$800 per pearl |
| A | $80-$300 per pearl |
| B | $20-$100 per pearl |
| C | $5-$60 per pearl |
| D | $1-$10 per pearl |
As you go up each grade, the value increases exponentially because of the rarity. Fine AAA and AAAA pearls can even occasionally sell for $2500 to $5000 per pearl at auctions.
Should I Buy Low Grade Pearls?
Lower grade C and D quality pearls are very affordable. But they are much less desirable for jewelry use because of the poor luster, blemishes and misshapen forms. It is recommended to buy at least grade B or A quality if you want pearls suitable for jewelry making and wearing.
The better luster, cleaner surface and white colors of fine grade pearls really make a difference compared to low grades. If budget is limited, consider buying one excellent strand of high grade pearls vs multiple strands of low grade.
How are Pearl Grades Certified?
Reputable pearl dealers will provide a grade certificate from an accredited gem lab like the GIA, AGS or GSI. The certificate guarantees the authenticity and grade of the pearls based on independent expert assessment.
Certified pearls graded by major labs hold their value better and can be resold easier. Jewelry appraisers also recognize certificates when evaluating pearl jewelry. Buy graded pearls with their original certificate whenever possible.
Should Grading Affect My Purchase?
Pearl grading gives an objective measure of quality, but your personal preference is still most important. If you find a strand of low A grade pearls that have beautiful, vibrant luster to your eye, those may be more appealing than a higher graded strand with a dull appearance.
See pearls in person before purchase whenever you can. An ugly AAA pearl is still not attractive! However understanding grades is key to finding quality pearls at fair prices.
How are Pearls Graded for Uniformity?
Beyond individual grade, pearl strands are also evaluated for uniformity of matching. Perfectly uniform strands where all pearls closely match have greater value than uneven strands with a wide variety of pearl sizes, shapes and colors.
Terms like “well-matched”, “close-matched” and “poorly-matched” describe this uniformity. Buy strands with higher uniformity grades for beautiful, coherent pearl jewelry.
Conclusion
Learning about the nuances of pearl grading gives you a better ability to shop for and evaluate pearls. Higher grades signify rarer quality that comes at a premium, while lower grades offer affordable options with imperfections. Consider your budget, intended use and preference to select a pearl grade suitable for your needs.