The 3rd C, "Clarity", is one of the rarity-in-nature factors that drives the price of a diamond. A Clarity Grade denotes the nature, size, position, number, and color of the natural inclusions inside a diamond. An inclusion is either an embedded mineral or a misalignment in the crystalline structure in a diamond while it was being formed. The freer from these natural "birthmarks" the diamond is, the rarer, and more expensive, it becomes.

"Clarity" for jewelry grade diamonds range from "Flawless" (FL & IF) to "Very, Very Slight" (VVS) to "Very Slight" (VS) to "Slightly Included" (SI) and finally to "Included" (I). These grades are then subdivided into high & low categories. Clarity grading is done using 10X magnification under controlled laboratory conditions.

In a jewelry grade diamonds, most internal inclusions and external blemishes have little effect on the brilliance, fire, and overall beauty of a diamond. So this is one area where the buyer can exercise budgetary control. For most viewers, "eye clean", that is, inclusions not visible to the naked eye without magnification, is the minimum threshold acceptable for jewelry purposes. Once again, the 1st C, "Cut" demonstrates its power, because the fire of a well cut stone distracts the eye from seeing what might otherwise be visible to the naked eye. The Clarity Grade necessary to achieve "eye clean" status varies with the visual sharpness of the viewer, the quality of the cutter’s art, and the nature of the setting in which the stone is held. As a result, at "Curtis Miller, Inc." we recommend that all stones be examined while still loose, so that "Clarity" can be easily perceived.

These charts will give a graphical representation to demonstrate the clarity grades.