A diamonds clarity grade is determined by the size, location, color, type and quantity of internal inclusions or external blemishes. Clarity grades begin at Internally Flawless and move towards I3 as these unique characteristics become more noticeable. Higher clarity grades are rarer and therefore more valuable.
The following is the Gemological Institute of America’s system of grading clarity
Flawless (FL) - No inclusions or blemishes are visible to a skilled grader using 10× magnification
Internally Flawless (IF) - No inclusions and only blemishes are visible to a skilled grader using 10× magnification
Very, Very Slightly Included (VVS1 and VVS2) - Inclusions are difficult for a skilled grader to see under 10× magnification
Very Slightly Included (VS1 and VS2) - Inclusions are clearly visible under 10× magnification but can be characterized as minor
Slightly Included (SI1 and SI2) - Inclusions are noticeable to a skilled grader using 10× magnification
Included (I1, I2, and I3) - Inclusions are obvious under 10× magnification and may affect transparency and brilliance
GIA CLARITY DIAGRAM EXAMPLES
CUT TIPS FROM AUCOIN HART
When evaluating a diamond’s clarity grade, a distinction should be made between a diamond’s rarity and its beauty. For example, while a VS2 clarity grade is considered rarer than a SI1, it may be less appealing if its inclusions are centrally located or black and more noticeable.