Clarity

Clarity refers to the presence (or absence) of impurities, blemishes or other identifying characteristics within a diamond.  Clarity characteristics are what make every diamond completely unique. There are no two diamonds that will have exactly the same inclusions in the same location. There are five factors that determine how a major laboratory like GIA or AGSL will assign a clarity grade to a specific diamond.
They include:

   Size: How large or small is an inclusion within a diamond?

GIA Clarity Grades

GIA has provided us with a universally understood method of describing clarity grades for diamond. 
There are five main clarity grades that can be found on your GIA or AGSL report.

GIA Clarity Grades:

Choose a Clarity Grade: FL-IF    VVS1-2    VS1-2    SI1-2    I1    I2-3

FL/IF Diamonds: Flawless: No inclusions under 10x.  Internally Flawless: None or only insignificant surface blemishes and no inclusions when examined under 10x. Normally, most blemishes can be removed by minor polishing.  Very rare, beautiful and expensive diamonds.

VVS1/VVS2 Diamonds: Very Very Slightly Included: Contain minute inclusions that are extremely difficult for an experienced grader to locate under 10x magnification. VVS diamonds are very rare and beautiful.

VS1/VS2 Diamonds: Very Slightly Included: Contain minor inclusions that range from difficult to somewhat easy to see under 10x magnification. Typical VS inclusions are small crystals, feathers or distinct clouds. In some rare cases, a VS stone can contain an eye visible inclusion.  Excellent quality diamonds.

SI1/SI2 Diamonds: Slightly Included: Inclusions are easily visible under 10x magnification to an experienced gemologist and may be visible with the unaided eye. A great value.

I1/I2/I3 Diamonds: Diamonds with inclusions that are visible to the unaided eye.

Which Clarity Grade to Choose?

It is important to select a diamond that does not have inclusions that will affect the overall beauty and durability of the diamond. If you want to be sure that your diamond will be completely clean of "eye-visible" inclusions, stick with diamonds graded "VS2" or higher.