Clarity refers to the number and size of minuscule defects, such as surface blemishes or internal flaws (inclusions) that naturally occur in the vast majority of diamonds. Many of these defects can only be seen under a microscope and have very little or no impact on the diamond’s appearance.
The clarity grades range from “internally flawless” (IF) and “flawless” (FL) at the top of the scale, to “included” (I) at the bottom.
For the best value, look for the so-called “eye-clean” diamonds often found within the “slightly included” (SI) clarity grade. Eye-clean diamonds do have imperfections, but they are not visible to the naked eye. Consult a professional to determine whether a particular SI diamond falls into the eye-clean category.