Diamond Clarity refers to the absence of internal inclusions or external blemishes.
Because Diamonds are created deep within the earth, most diamonds contain unique birthmarks called inclusions and blemishes. Diamonds with very few birthmarks are rare and, of course, rarity affects a diamond's value. Using the International Diamond Grading System, diamonds are given a clarity grade that ranges from flawless (FL) to diamonds with more prominent inclusions (I3).
Every diamond is unique. But none are absolutely perfect even though some come close, even under 10X magnification. Known as flawless diamonds, they are exceptionally rare.
This Clarity Scale contains 11 grades, with most readily available diamonds falling into the VS or SI categories. In determining a clarity grade, you must consider the size, nature, position, colour or relief, and quantity of clarity characteristics visible under 10X magnification.
Flawless (FL) - No inclusions or blemishes are visible to a skilled grader using 10X magnification
Internally Flawless (IF) - No inclusions and only minor blemishes are visible to a skilled grader using 10X magnification
Very, Very Slightly Included (VVS1 and VVS2) - Inclusions are difficult for a skilled grader to see under 10X magnification
Very Slightly Included (VS1 and VS2) - Inclusions are clearly visible under 10X magnification but can be characterized as minor
Slightly Included (SI1 and SI2) - Inclusions are noticeable to a skilled grader using 10× magnification
Imperfect (I1, I2, and I3) - Inclusions are obvious under 10X magnification and may affect transparency and brilliance