how IAG grades diamonds

the trusted name

Objectivity and independence are the hallmarks of all IAG reports and services. All diamonds are assigned with a unique internal identification number that is used to track it throughout the process.


All items submitted to IAG for diamond grading services are examined and further determined if the material is a natural diamond, laboratory-grown or non-diamond material.


The colour grade of a diamond is determined when there are sufficient agreeing opinions.


Clarity is graded with 10x magnification under standard viewing conditions. The preliminary grader carefully examines the diamond to locate clarity/finish characteristics and evidence of any diamond treatments, such as fracture filling or laser drilling.


Depending on the diamond’s weight, quality, and the agreement of grading opinions, additional quality assurance process steps are performed. Experienced gemologists review all of the previous grading information and render independent clarity/polish/symmetry opinions. Grading results are finalised once there are sufficient agreeing opinions.


IAG provides a cut quality grade only for standard round brilliant diamonds that fall in the GIA D-to-Z colour range. After the colour and clarity grading process, the diamond’s proportions (measurements and facet angles), along with polish and symmetry descriptions, are used to determine its Cut Grade.


At every step of the grading process, special inspection, care, and handling procedures are in place to protect a diamond’s identity and ensure the diamond is managed with the utmost care.

Verify Your Report

IAG Report Check provides you with an additional level of assurance. A quick and convenient way for verification of information on your report with IAG’s report database.

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