The 4Cs of Diamond Grading

Clarity
Diamonds can have internal characteristics known as inclusions or external characteristics known as blemishes. The fewer inclusions or blemishes, the more rare the diamond. Inclusions are internal, that is, inside the diamond. Two common inclusions are crystals and feathers. Crystals are merely minerals trapped inside the diamond; feathers are breaks in the diamond. Blemishes are usually very small and are only found on the surface of diamonds. These may be a result of the polishing process or through the wear of the diamond.

When a diamond is graded for clarity, the diamond grader uses a binocular microscope and specific lighting to locate, identify and plot the diamond’s characteristics, then considers the effect these have on the diamond’s appearance and/or durability. The grader assigns a final grade with a 10x loupe. Diamonds without inclusions or blemishes are rare; however, most characteristics can only be seen with magnification.

To learn more about the American Gem Society Diamond Cut Grade Scale go to our Diamond Clarity Grade page under the AGS Grading System menu.