Do all diamond dealers use the same grading method? Unfortunately no! Some dealers choose to use diamond grading methods of their own design which complicates things considerably. Potentially, the use of a grading system that is not standardized could make comparison shopping quite difficult, especially for the novice.

However, there are two universally recognized grading methods that will make it easy for you to know what you are comparing. The Gemological Institute of America (GIA) and the American Gem Society (AGS) methods are the only world-wide recognized systems. Here are the comparison charts for GIA and AGS for you to use when comparison shopping.

Let’s assume the store you’re visiting is using the AGS grading system. Converting the AGS grades, 0 through 10 for color and clarity, into the GIA grading system is rather easy. If the color is graded AGS 2.0 then the GIA equivalent is H. Feel free to print these charts and keep them with you when shopping for your diamond.