How GIA Grades a Diamond?

GIA Grading
GIA Certification
Important Diamond Facts

Everyone might be familiar with the terms GIA grading or GIA certification. GIA is an agency which grades diamonds based on their quality. A diamond with a GIA certificate will have all the qualities which are desired in a diamond. So it is important to buy a diamond with GIA grading for you to get a high quality diamond which is worth the amount you spend.

Even though most people are familiar with GIA certificates, many people are still oblivious to how a GIA grading is done. In this article we are providing some information associated with the process involved in GIA certification.

Anyone can submit a diamond to GIA for certification, from the diamond cutter or retailer to the end customer.

GIA begins its grading process as soon as the diamond reaches its laboratory. The diamond can be send from anywhere in the world through courier or in person. The diamond that is submitted for evaluation should not include any logos names or any letters or words that will reveal the identity of the owner to the GIA personnel. A tracking number will be assigned to each diamond to identify it throughout the grading process.

Then GIA will analyze the following characteristics of the diamond for the grading process:

Carat Weight and Proportions

The diamond will be weighed and measured using an electronic micro-balance that will capture the carat weight accurately. Then the accurate measurements of the diamond will be analyzed using an optical scanning device. It will also check the proportions and facets of the diamond.

Then additional tests are done to find out whether the diamond is natural or synthetic or if the color is lab induced.

Clarity and Finish

Multiple graders will check the clarity of the diamond under magnification. The grader will make sure that the data from the prior step is accurate and will look for the presence of any treatments on the diamond. Then its polish and symmetry will be also verified.

Color and Fluorescence

Next, the color of the diamond will be compared to a set of master stones to determine its color grade. A step by step detailed comparison will be done with the master diamonds to determine which color grade the diamond falls in. After this, the diamond will be observed under special UV light to check its fluorescence.


The next step is the analysis of its cut. In this step the diamond’s brilliance, fire brightness, scintillation etc will be assessed. The cut grade will also include the factors like proportions, symmetry, facet angles, polish etc.

After the analysis is complete, GIA will issue the final certificate for the diamond based on all this factors. It will be printed with micro print lines along with a hologram and other security measures, and will be laminated to prevent its tampering. Then the report will be delivered to the owner of the diamond in a protective sleeve.

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