How To Read A GIA Diamond Certificate

by Ultimate Jewelry Guide
How To Read A GIA Diamond Certificate

When you buy a diamond, the most important document you will look at is the diamond certificate. The certificate is a document that describes the diamond’s authenticity and characteristics. However, most people don’t know that not all certifications are equal.

This blog post will talk about the Gemological Institute of America (GIA) certificate and why it is considered an industry standard. This blog post will teach you how to read a GIA diamond certificate.

What Is A GIA Diamond Certificate?

A GIA Diamond Certificate is a document that shows the characteristics of a diamond, such as its cut, color, clarity, and carat weight. It also includes the diamond’s measurements and an evaluation by a GIA Graduate Gemologist.

The GIA Certificate protects the diamond’s value. It is also known as the Diamond Grading Report. It also protects the consumer from deception and misrepresentation, as it guarantees quality.

How To Read A GIA Diamond Certificate

Reading a GIA Diamond Certificate is simple. However, one must know the various formations and designations used in the report. Below is how you can read and interpret the GIA Diamond Certificate using the GIA Certificate five sections.

1. The Heading

The heading holds the basic information about the diamond. You should;

Confirm the GIA Logo

When it comes to the logo, you should confirm that it is a GIA Diamond Certificate. The certificate has the laboratory’s name, which is the “Gemological Institute of America.” If written in short, confirm the initials are “GIA.”

Check for the Serial Number and Report Type

If you are purchasing a diamond, you should confirm whether it has been certified. You can check this at the top of the report. The type of report issued by GIA is also indicated on the left side of the certificate. If there is no serial number, the diamond has not been certified.

The serial number is also encrypted on the diamond. While viewing under a microscope, you should confirm that you are holding the certified diamond.

Check the date

The GIA Certificate has the date of issuance and when the diamond was submitted for evaluation. The dates are at the top left corner of the certificate.

It is essential to check these dates because it will help you avoid buying a diamond that has been on the inventory for too long. If a diamond has been in stock for more than six years, it is advisable to consider its clarity and price before buying.

Shape and Cutting Style

The shape of the diamond is indicated on the left side of the certificate. It can be a round brilliant, heart, oval, emerald, or any other shape you may want to buy. The cutting style will also depend on your preference and budget.


The measurements of the diamond are indicated on the left side, just below its shape. The sizes are in millimeters and mark the length, width, height. With these dimensions, you will have an idea about how big your stone is without holding it physically.

2. The Grading Results

In this part, you should check out the 4cs;

Carat weight

The carat weight is the first characteristic evaluated. It is also the most crucial factor when it comes to diamonds. The GIA Certificate will state the diamond’s weight in carats and points. 


The clarity is next on the list and is graded from included to flawless. The certificate will state a grade, such as “I,” which stands for Included.


The cut of the diamond is also evaluated and given a grade. It can be Excellent, Very Good, Good, Fair, or Poor. 


Lastly, you have the diamond’s color. The GIA Certificate will state the diamond’s grade from D (no hue) to Z (a yellow-hued diamond).

The certificate also includes an image of the diamond so you can better understand what it looks like.

3. Additional Grading Information

This is information that supplements the diamond’s grading. 


The polish is graded from Excellent to Poor. 


The symmetry is graded from Excellent to Poor. 


The fluorescence is graded from None, Faint, Medium, Strong, or Very Strong. 


This includes any other remarks that the grader has about the diamond. 


The certificate also shows the inscriptions on the diamond. This might include a logo or a serial number.

Certifying Authority

The certifying authority is the independent organization that validates the diamond’s grading results. 

4. Proportions

This section shows the diagrammatic representation of the diamond’s cut. The diagrams help you understand if the cutting style suits your preference. The drawings include;

Proportion diagram

This diagram is a graphical representation of the diamond’s height, depth, table size, and angles. 

Plotted diagram

This diagram plots the top view of the diamond and helps understand the diamond’s symmetry. The diagram shows locations of inclusions and blemishes on the diamond’s surface.

Key to symbols

This key will help you understand the inclusions on the plotted diagram. The keys include different inclusions like; feather, needle, and cloud.

5. Grading Scales

The grading scales show the different grades and their corresponding measurements. The scales are outlined by GIA to be used as a reference. In this section, be sure to look out for;

Cut Scale

The cut plays a significant role in a diamond and its appearance. GIA cut scale ranks the diamonds from poor to excellent.

Clarity Scale

This scale rates clarity from included to flawless. The scale shows the different grades and their measurements.

Color Scale

This scale rates color from D (no hue) to Z (a yellow-hued diamond). The scale shows the different grades and their corresponding measurements.

Why Are GIA Certifications Important?

When buying a diamond, it is essential to have the GIA Certification. The certification assures that an impartial and expert organization has graded the diamond. It also guarantees that the grading results are accurate.

The GIA Certificate is your assurance of quality and helps protect you from purchasing a counterfeit or poor-quality diamond. The certificate also allows you to resell the diamond at a later period.


Now that you know how to read a GIA diamond certificate, you can be sure that you are getting the quality of diamond that you expect. By understanding what each section means, you can feel confident in your purchase and know that your diamond is conflict-free.

You may also like

Leave a Comment