Natural diamonds are formed deep within the earth under extreme heat and pressure. They often contain a variety of characteristics called inclusions and blemishes. Diamond clarity refers to the absence of these characteristics. Diamonds without these birthmarks are rare, and rarity affects a diamond’s value. Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. Every diamond is unique. None is absolutely perfect under 10× magnification, though some come close. Known as Flawless diamonds, these are exceptionally rare.
Many inclusions and blemishes are too tiny to be seen by anyone other than a trained diamond grader. To the naked eye, a VS1 and an SI2 diamond may look exactly the same, but these diamonds are quite different in terms of overall quality.
The GIA Clarity Scale contains 11 grades, with most diamonds falling into the VS (very slightly included) or SI (slightly included) categories. In determining a clarity grade, the GIA system considers the size, nature, position, color or relief, and quantity of clarity characteristics visible under 10× magnification.
- 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 minor and range from difficult to somewhat easy for a skilled grader to see under 10x magnification
Slightly Included (SI1 and SI2) – Inclusions are noticeable to a skilled grader under 10x magnification
- Included (I1, I2, and I3) – Inclusions are obvious under 10× magnification and may affect transparency and brilliance