How to Read a GIA Diamond Grading Certificate

A diamond should come with a report from the Gemological Institute of America (GIA) or similar gemological organization or laboratory that contains a full scientific and unbiased assessment of your diamond’s 4Cs (cut, clarity, color and carat). While these reports contain a lot of detailed information and can seem overwhelming, they are relatively easy to read and understand.  

What’s Included on a GIA Diamond Certificate? 

GIA is considered the gold standard among the industry’s most reputable jewelers and diamond dealers. It’s a dossier, first developed in the 1950s that documents and assesses a diamond’s characteristics as well as a lot of other information. The purpose of an unbiased GIA report is to verify what the jeweler/seller is telling you.

A GIA Diamond Certificate will contain the following information:

  • A unique certificate number 
  • A description of the shape of the diamond 
  • The carat weight of the diamond 
  • The color of the diamond 
  • The clarity of the diamond
  • The length, width and depth of the diamond in millimeters 
  • A description of the cut grade 
  • The quality of the diamond’s polish 
  • The quality of the diamond’s symmetry 
  • The presence or absence of fluorescence in the diamond 
  • The total depth percentage and table percentage of the diamond 
  • A description of the girdle’s appearance 
  • A description of the culet 
  • Additional notes of interest

The diamond report simply outlines the details of a diamond’s individual characteristics, it is not an appraisal and does not suggest a monetary value.

How to Read a GIA Diamond Grading Certificate

Every diamond is unique with a range of characteristics that you could think of like a fingerprint. These characteristics are what ultimately determine the diamond’s value, and are recorded on a diamond certificate. If you’ve ever wondered where a diamond’s price comes from, you’ll soon realize it’s not just about the size of the gem or the store where you get it. 

Did you know diamonds are graded on the absence of color using a scale of D to Z where Z would indicate some yellow or brown color? After the cutting style and measurements, you’ll find color, clarity and cut grades. The finish of the diamond is influenced by two factors: polish and symmetry. Polish is an indication of how smooth the surface is and symmetry is the comparison of how the stone’s facets are shaped, positioned and aligned in relation to one another.

You’ll also find a description of the diamond’s fluorescence properties which is the intensity and color it glows with when exposed to ultraviolet (UV) light. The clarity plot diagram is a graphical representation of the diamond’s “fingerprint” and identifies any flaws or blemishes. You’ll also see a very detailed proportions diagram.

We carefully inspect our GIA certified diamond inventory to provide stunning options based on grading, visual brilliance and beauty. Learn more about our GIA approved process here or contact us with questions.