Learn About Pearl Grading

Pearl Grading

Our Comprehensive Pearl Grading Guide

There are, what seems like, endless different standards for grading systems that are used throughout the world when it comes to pearl grading. Unfortunately, there is no universal standard. Each standard varies in value factors and verbiage, but we can help you understand what each of these standards represents.

Some of the most common pearl grading systems include:

  • Japanese Grading (Mikimoto Grading)
  • Tahitian Grading System
  • Chinese Grading System
  • Kyllonen Grading System

Each system uses the same basic standards but tends to use different terminology. Here we’ll unravel the mystery of pearl grading, and if you’re interested in what factors gives pearls their values, we can help you out with that too.

How Pearl Grading Works

Abiding by strict quality controls results in quality and trust and that’s exactly what pearl grading sets out to do. By following a certain set of standards, pearl graders can distinguish the finest quality pearls from the average ones. This process is long and tedious but most definitely worth it.

Pearls are graded often by color, shape, size, luster,and blemish. The finest pearls are selected for loose pearl sales while others are sorted and used for pearl strands. Strands and loose pearls are generally graded on slightly different scales. Loose pearls have tighter restrictions compared to pearl strands.

Kyllonen uses the highest standards and only accepts and sells the very best pearls available. To begin, we’ll start off with our very own standard grading system.

Kyllonen Grading System

The Kyllonen grading system was developed to remove any ambiguity from the world of pearl grading. Kyllonen separates grading between loose pearls and strands. Loose pearls are graded by individual beauty, whereas strands are graded on overall beauty and matching.

We use the same pearl grading system for each type of pearl to promote consistency and avoid confusion. This makes it easy for our customers to understand exactly what they are purchasing. Kyllonen uses the highest quality standards to ensure we use only the most beautiful pearls in the world.

Kyllonen Loose Pearl Grading Scale

As we stated before, Kyllonen uses two separate systems to grade loose pearls and pearl strands. Here, we’ll let you in on each and every factor that affects the grade of a loose pearl:

Gem Grade Pearls

Gem grade pearls are the best in the world. They display the highest luster with a mirror-like reflection. Gem grade pearls show rich color and orient. When featured in jewelry, these pearls show no flaws or blemishes. This category is generally not used for South Sea White or Gold Pearls.

Kyllonen Gem Grade Loose Pearls  
Surface No visible blemish
Luster Excellent
Color High saturation or orient


Kyllonen Pearl Strand Grading Scale

Pearl strands are graded collectively. So instead of each pearl being graded individually, a pearl strand is graded as one. Pearl strands high in value will have high-quality matching, lustrous, and blemish-free pearls.
Kyllonen Heirloom Pearls Kyllonen Gem Quality Pearls Kyllonen AAA Pearls Kyllonen AA+  Pearls
Information Heirloom pearl strands are composed of the finest available pearl strands on the market. Each pearl is hand-selected from Gem Quality loose pearls making them truly the best of the best. Gem Quality strands contain some of the finest pearls available including Tennyo strands. These pearl strands exhibit virtually no flaws or deep flaw inclusions. AAA pearls are higher quality than the majority of most pearls on the market. Pearls receiving a AAA grade carry great qualities that suit them beautifully for pearl strands and loose jewelry alike. AA+ is the lowest quality carried by Kyllonen, however, these pearls are beautiful and look flawless to the naked eye. Only under close inspection can one see the flaws that AA+ pearls carry.
Surface 100% blemish free to the naked eye 98% blemish free 95-98% blemish free 90-95% blemish free
Luster Excellent Excellent Very good to excellent Very good to excellent
Shape Round Round (freshwater round to near round) Round (freshwater round to near round) Round (freshwater round to near round)
Color High saturation or orient High saturation or orient - -
Matching Excellent Excellent Excellent Excellent

Other Pearl Grading Systems

As we discussed earlier, there is a variety of pearl grading systems used today. And although at Kyllonen we use our in-house grading scale, it’s crucial that you understand the variety of other grading scales used commonly today. This way, you ensure you make the most informed decision when purchasing pearl jewelry.

Japanese Grading System (Akoya Pearls)

The Japanese Standard Grading system uses an A-AAA system in addition to the special grades of Tennyo and Hanadama. This system was originally created by Mikimoto, an infamous idol in the pearl industry.

Since it has been around for so long, the A-AAA system is the basis of grading for all pearl grading systems. However, it’s important to realize that not every pearl company’s AAA is equivalent to another company’s AAA.

In the Japanese Grading System, Tennyo and Hanadama grades require a minimum of 0.4mm nacre thickness. The higher the standards of the company, the better the quality of each category.

Japanese Special Grades

Tennyo Akoya Pearls

Nicknamed the "Goddess", Tennyo is the highest available grade for Japanese Akoya pearls. The Tennyo grade is achieved by earning 90 out of 100 points on the PSL system. This grade heavily relies on luster and orient - which ultimately give the pearl its beauty.

Generally, the Tennyo grade is used for pearl strands and pearl earrings.

Hanadama Akoya Pearls

Also known as the "Flower Pearl", the Hanadama is the 2nd highest grade for Japanese Akoya pearls based on the PSL system. Hanadama was originally the highest grade available before Tennyo was introduced to further distinguish the highest quality pearls.

Generally, the Hanadama grade is used for pearl strands or pearl earrings.

Japanese Akoya Standard Grades

When it comes to Japanese Akoya pearls, the standard grades are AAA, AA+, AA, and A with AAA being the highest. This scale was developed by the infamous Kokichi Mikimoto to create standardization in the chaotic world of pearl grading.
Japanese AAA Akoya Pearls Japanese AA+ Akoya Pearls Japanese AA Akoya Pearls Japanese A Akoya Pearls

AAA is the highest of the standard loose Akoya pearl grades that is not accompanied by a Certificate. This represents less than 3% of the pearl harvest making this grade of Akoya pearls extremely rare and high in value.

AA+ is the 2nd highest standard loose Akoya pearl grade that is not accompanied by a Certificate. This represents less than 10% of the pearl harvest. AA is a standard pearl available at many common retail stores. This represents around 20% of the pearl harvest. A is the lowest grade for loose Akoya pearls. This represents around 50% of the pearl harvest.
Surface 95% blemish free 90% blemish free 80% blemish free 70% blemish free
Luster Excellent Excellent Excellent Fair to good
Shape Round Round Round Round

Tahitian Grading System

The Tahitian Standard Grading System was first introduced by the Tahitian government in order to regulate the quality and reputation of the Tahitian Black Pearl. Pearls exported from Tahiti undergo inspection to assure proper nacre thickness and overall pearl quality. There is still some ambiguity in surface quality, which is common throughout many other pearl grading systems.

Tahitian Special Grade Pearls

Tahitian Gem Grade Pearls

Gem Grade Tahitian Black Pearls are special pearls which display the highest value of every factor. These pearls represent less than 3% of the pearl harvest and are therefore extremely rare.

Tahitian Gem Grade Quality  
Surface 95% blemish free
Luster Excellent
Shape Round
Color High saturation

Tahitian Standard Grade Pearls

The standard Tahitian grading scale grades pearls on a scale from A to D - A being the highest and D being the lowest.
A Tahitian Pearls A/B Tahitian Pearls B Tahitian Pearls C Tahitian Pearls D Tahitian Pearls
Tahitian A Grade Quality Tahitian A/B Grade Quality Tahitian B Grade Quality Tahitian C Grade Quality Tahitian D Grade Quality
Information A is the top standard quality available for Tahitian Black Pearls. This represents less than 5% of the pearl harvest. A/B Tahitian Black Pearls represents around the top 10% of the pearl harvest. These pearls usually show a luster similar to A grade pearls with slightly more surface blemish. B Tahitian Black Pearls represent the top 20% of the pearl harvest. These pearls exhibit great beauty with a few small blemishes. C grade Tahitian Black Pearls display less luster and have more surface flaws than the higher grades. These pearls represent 30% of the total harvest. D is a commercial grade for loose Tahitian Pearls which are not exported from Tahiti. This grade represents over 30% of the pearl harvest.
Surface 90% blemish free 80% blemish free 70% blemish free 60% blemish free Over 60% blemished
Luster Very good to excellent Very good to excellent Good to very good Fair to good Fair
Shape Round Round Round Round Round

Chinese Standard Grading System

The Chinese Standard Grading System is the most ambiguous grading systems used for pearls. This is due to a lack of an overall market leader or government entity standardizing the grading forefront. Pearl grades in China started using the AAA system and then developed into something entirely different over the years.

Over time Chinese sellers have attempted to outdo one another and started claiming 4A, 5A, and even  6A pearls. This led to mass confusion within the market. The largest pearl companies in China now use a 5A system as the standard with 5A representing Gem Grade pearls and 4A being the equivalent to a AAA in the Japanese System.

5A Chinese Standard Pearls 4A 1 Chinese Standard Pearls 4A 2 Chinese Standard Pearls 3A 1 Chinese Standard Pearls 3A 2 Chinese Standard Pearls Commercial Grade
Chinese 5A Quality Chinese 4A 1 Quality Chinese 4A 2 Quality Chinese 3A 1 Quality Chinese 3A 2 Quality Commercial Grade Quality
Information AAAAA is the highest grade in the Chinese Standard Grading System and is considered a special grade by many Non-Chinese pearl companies. These pearls look similar to Akoya pearls and are less than 1% of the pearl harvest. AAAA1 freshwater pearls are equivalent to AAA pearls used by Japanese grading standards. These pearls make up less than 3% of the pearl harvest. AAAA2 pearls are equal to AA+ in Japanese grading standards. These pearls represent less than 5% of the pearl harvest. AAA is equal to AA by Japanese grading standards. This represents less than 10% of the pearl harvest. AAA2 is equal to A by the Japanese grading standard. These pearls represent less than 20% of the pearl harvest. This is the lowest grade of freshwater pearls and represents over 60% of the pearl harvest.
Surface 95% blemish free 90% blemish free 80% blemish free 80% blemish free 70% blemish free Less than 70% blemish free
Luster Excellent Very good Very good Good Fair to good Poor
Shape Round to near round Round to near round Near round Near round Near round to off round Round

The world of pearl grading is inevitably confusing. Hopefully, you’ve gained some valuable insight into this subject. For the highest grade pearls possible, be sure to shop with Kyllonen Luxury today!