The GIA Clarity Scale includes eleven clarity grades ranging form Flawless to I3. Because diamonds form under tremendous heat and pressure, it is extremely rare to find a diamond that lacks any internal and external characteristics. These characteristics are a by-product of its formation and help gemologists and jewelers separate natural diamonds from synthetics and simulants, and identify individual stones.
FL - Flawless Shows no inclusions or blemishes of any sort under 10X magnification when observed by an experienced grader.
IF - Internally Flawless Has no inclusions when examined by an experienced grader using 10X magnification, but will have some minor blemishes.
VVS1 and VVS2 - Very, Very Slightly Included Contains minute inclusions that are difficult even for experienced graders to under 10X magnification.
VS1 and VS2 - Very Slightly Included Contains minute inclusions such as small crystals, clouds or feathers when observed with effort under 10X magnification.
SI1 and SI2 - Slightly Included Contains inclusions (clouds, included crystals, knots, cavities and feathers) that are noticeable to an experienced grader under 10X magnification.
VS1 and VS2 - Very Slightly Included Contains minute inclusions such as small crystals, clouds or feathers when observed with effort under 10X magnification.
SI1 and SI2 - Slightly Included Contains inclusions (clouds, included crystals, knots, cavities and feathers) that are noticeable to an experienced grader under 10X magnification.
I1, I2 and I3 - Included Contains inclusions (possible large feathers or large included crystals) that are obvious under 10X magnification and may affect transparency and brilliance.
Sample Inclusions on Real Diamonds
Feather or Cloud Inclusions
Feather or Cloud Inclusions
Sample Inclusions on Real Diamonds
A picture of a loupe
An inspectors using a different kind of loupe to check the diamond for clarity.