Clarity:
Virtually all natural diamonds contain identifying characteristics, yet many are invisible to the naked eye. Clarity is a measure of internal defects of a diamond called inclusions. Inclusions may be crystals of a foreign material or another diamond crystal, or structural imperfections such as tiny cracks that can appear whitish or cloudy. The number, size, color, relative location, orientation,and visibility of inclusions can all affect the relative clarity of a diamond. The Gemological Institute of America (GIA) and others have developed systems to grade clarity, which are generally based on those inclusions which are visible to a trained professional when a diamond is viewed from above under 10x magnification.

The clarity scale is broken down into the following grades:

SYMBOL MEANING DEFINITION
F Flawless Free from all inclusions or blemishes.
IF Internally Flawless No inclusions visible at 10x magnification.
VVS1 Very Very Slightly Included #1 Inclusions that are extremely difficult to locate at 10x magnification.
VVS2 Very Very Slightly Included #2 Inclusions that are very difficult to locate at 10x magnification.
VS1 Very Slightly Included #1 Minor inclusions that are difficult to locate at 10x magnification.
VS2 Very Slightly Included #2 Minor inclusions that are somewhat difficult to locate at 10x magnification.
SI1 Slightly Included #1 Noticeable inclusions that are easy to locate at 10x magnification.
SI2 Slightly Included #2 Noticeable inclusions that are very easy to locate at 10x magnification.
I1 Included #1 Obvious inclusions. Somewhat easy to locate with the unaided eye.
I2 Included #2 Obvious inclusions. Easy to locate with the unaided eye.
I3 Included #3 Obvious inclusions. Very easy to locate with the unaided eye.

The above clarity grading scheme is in accordance with the GIA (Gemological Institute of America). It is important to note that the GIA Grading system is not static, and has changed slowly over time.

To learn more about the 4 C's, click on the respective link below:

Cut Color Clarity Carat Weight