Decoding a Diamond Grading Report Before Selling Your Diamond

GIA report

Before you start selling your diamond, it’s important that you truly understand everything about the stone, including all the smaller details. This way, you know if you are getting a fair price and can ensure that you get the best possible deal.

There are a lot of factors that determine the price of a diamond. One of the best ways to understand these factors is to analyze your diamond grading report. Reports from reputable organizations like the Gemological Institute of America (GIA) are a great resource that you can use to get familiarized with your diamond.

We’re here to help you decode a GIA grading report so that you can make sure you are getting the best possible value for your diamond! Here is each component broken down that you will find on most diamond grading certificates:

1. Laser Inscription Registry
Every diamond that is certified by the GIA actually has a laser inscription on the stone itself. Each diamond is micro-laser inscribed with its own unique GIA certificate number. So, the number that you see on your report can be found on the corresponding diamond that you own.

2. Shape and Cutting Style
There are a lot of different shapes that a diamond can be. Some examples of diamond shapes include round, oval, heart, cushion, or pear.

The diamond’s cutting style refers to the facet arrangement on the diamond. You can think of diamond facets as flat faces on the surface of the diamond that you can see if you look at it closely. As you move the diamond around, you’ll see the different facets light up and the geometric patterns that are created by the facets. Examples of diamond cuts include brilliant, princess, step, mixed, or emerald.

3. Measurements
This is a simple measure of the size of your diamond. For round diamonds, the measurements would be presented in the following format: minimum diamond – maximum diamond x depth. Fancy shape diamonds would be measured like: length x width x depth.

These measurements are calculated to the hundredth of a millimeter, so they are extremely accurate. You’ll know the exact size and dimensions of your diamond by looking at this part of the report.

4. Carat Weight
The carat weight of your diamond is determined by the weight of the stone. To calculate this number, the diamond was weighed to the thousandth of a carat with a digital measuring device by GIA. You can think of carat size by knowing that two carats is roughly the weight of a small paper clip.

On your diamond grading certificate, you’ll see an exact measure of the total carat weight that was determined by GIA.

5. Color Grade
The color of a diamond is determined how much yellow is present in the stone. The ideal color for your diamond would actually be “colorless,” meaning that the stone is not yellow at all.

GIA has developed a scale to rank the color of diamonds relative to one another. Your diamond has been compared to a master set of color comparison stones under special lighting to determine it’s grade. The color scale that is used ranges from the best grade of D, down to Z. So, a diamond that is considered colorless has a rating of D, E, or F.

6. Clarity Grade
Determining a diamond’s clarity grade is all about the number, size, placement and nature of internal flaws of blemishes on the stone. Sometimes you can see these flaws with your naked eye, but other times you would have to use magnification in order to even see the imperfections on the diamond.

And just like with color grade, the GIA has created a scale to rank diamonds for their clarity. The best, most flawless diamonds receive a grading of IF and the scale goes all the way down to I3. The grade given to the stone by the GIA is based only on what is visible under 10x magnification.

7. Cut Grade
When considering a diamond’s cut, GIA is looking at how the facets and angles of a diamond work together to reflect light. This is really the one factor of a diamond that has the biggest impact on the sparkle, brightness and beauty of a diamond.

A well cut diamond is desirable and valuable when it has a distinctive and tremendous light return, aka sparkle and fire. In contrast, a poorly or moderately cut diamond doesn’t reflect much light back towards your eyes. So a poorly cut diamond appears flat, lifeless, dull and apparently dirty even when it is perfectly clean.

So, your diamond’s cut is an important part of the final price you will end up receiving for your stone.

8. Finish
The finish of your diamond refers to the polish of the stone and how symmetrical, or how evenly, the facets have been placed on the surface.

9. Fluorescence
The fluorescence of your diamond refers to its reaction to long wave ultraviolet radiation. You don’t want a diamond with too much fluorescence because this is less desirable. The fluorescence of a diamond ranges from none to a very strong yellow.

The comments section of any diamond grading report is a place used to note any characteristics of the diamond that are not discussed elsewhere. It’s also a way to mention items not plotted on any of the diagrams.