The pearl grading system differs significantly from other gemstone grading systems, lacking a standardized approach within the industry. Each company employs its own subjective and unique grading system. While various grading systems exist, most reputable pearl sellers commonly use either the AAA-A or A-D quality classifications.

Understanding the Pearl Grading Scale:

1. AAA-A Scale:

• Very High: AAA

• High: AA+

• Medium: AA

• Low: A

2.      A-D Scale:

• Very High: A

• High: B

• Medium: C

• Low: D

It is important to note that the grading results may vary from one company to another due to the absence of a universal standard. For instance, one company may rate a pearl with high quality as AA+, while another may assign a higher grade of AAA to a pearl with lower luster.

The AAA-A scale is primarily used for evaluating Akoya and freshwaterpearls, but some sellers also apply it to South Sea and Tahitian pearls. In contrast, the A-D scale, known as the "Tahitian System" in French Polynesia, is exclusively used for grading Tahitian and South Sea pearls. This scale is the standard in pearl-producing countries, although some sellers still prefer to use the AAA-A scale for these types of pearls.

Pearl Grading Charts:

To offer a clearer understanding, the following are grading charts for different types of pearls. These charts serve as guidelines for what to expect at various grade levels, recognizing that each company may have its own grading standards.

South Sea Pearl Grading Chart:

• AAA / A

• Very High Grade

• AA+ / B

• High Grade

• AA / C

• Medium Grade

• A / D

• Low Grade

Characteristics:

• Very High Grade: Clean surface with 95% or more coverage; very high lustre.
• High Grade: Surface with 5% or fewer slight imperfections not visible to the naked eye; excellent to very good lustre.
• Medium Grade: Moderate surface imperfections; very good lustre.
• Low Grade: Surface with noticeable imperfections; lower lustre.

Tahitian Pearl Grading Chart:

• AAA / A

• Very High Grade

• AA+ / B

• High Grade

• AA / C

• Medium Grade

• A / D

• Low Grade

Characteristics:

• Very High Grade: Clean surface with minimum 95% coverage; very high lustre.
• High Grade: Surface with 0-5% or fewer slight imperfections not visible to the naked eye; excellent to very good lustre.
• Medium Grade: Moderate surface imperfections; very good lustre.
• Low Grade: Surface with noticeable imperfections; lower lustre.

Akoya Pearl Grading Chart:

• AAA

• Very High Grade

• AA+

• High Grade

• AA

• Medium Grade

• A

• Low Grade

Characteristics:

• Very High Grade: Clean surface with at least 95% coverage; thick nacre (0.4mm or more); perfectly round; excellent to very good lustre; pearls match almost perfectly in strands.
• High Grade: Surface with 5% or fewer blemishes not visible to the naked eye; thick nacre; excellent to very good lustre; nearly round shape.
• Medium Grade: Surface with moderate blemishes; moderate nacre thickness; good lustre; mostly round.
• Low Grade: Surface with noticeable blemishes; thinner nacre; lower lustre; round or slightly irregular shape.

Freshwater Pearl Grading Chart:

• AAA

• Very High Grade

• AA+

• High Grade

• AA

• Medium Grade

• A

• Low Grade

Characteristics:

• Very High Grade: Clean surface with minimum 95% coverage; very minor blemishes (0-5% coverage); round shape; excellent lustre; pearls match well in strands.
• High Grade: Surface with slight blemishes; round shape; good lustre; good match in strands.
• Medium Grade: Surface with some imperfections; mostly round shape; moderate lustre; reasonable match in strands.
• Low Grade: Surface with visible imperfections; non-round shapes; lower lustre; significant differences between pearls in strands in terms of color, shape, size, and surface quality.