Clarity is the degree to which a diamond is free from flaws, which can hinder light as it passes through your diamond.
Like people, diamonds have "birthmarks" that vary in size, shape, position, quantity and color. These birthmarks are known as inclusions (internal) and blemishes (external). Inclusions are formed deep in the earth during the diamond's growth. Blemishes can result from the diamond-cutting process.
The clarity grade is determined based on the size, number, position of, nature and color of the diamond's blemishes.
Though nearly all diamonds have inclusions and blemishes, the most prized diamonds are flawless.
The clarity scale, developed by the Gemological Institute of America (GIA), has 11 grades:
- F (flawless inside and out)
- IF (internally flawless, which means there are blemishes on the surface but not inside the diamond)
- VVS1 and VVS2 (very, very slightly included - two levels)
- VS1 and VS2 (very slightly included - two levels)
- SI1 and SI2 (slightly included - two levels)
- I1, I2 and I3 (included - three levels)
It may be difficult to see inclusions with the naked eye, depending on where they are located within the diamond. But every diamond is unique, so you need to look closely. If you view an SI2 diamond and can't see the inclusions without a jeweler's loupe, you can probably accept a lower grade and save on cost without compromising beauty.