GIA Diamond Clarity Scale
Flawless or FL :
No inclusions or blemishes are visible to a skilled grader using 10x magnification.
Internally Flawless or IF :
No inclusions, only blemishes are visible to a skilled grader using 10x magnification.
Very Very Slightly Included or VVS1/ VVS2 :
Inclusions are difficult to detect for a skilled grader under 10x magnification.
Very Slightly Included or VS1/ VS2 :
Inclusions are negligible and range from difficult to somewhat easy for a skilled grader to detect it under 10x magnification.
Slightly Included or SI1/SI2 :
Inclusions are obvious to a skilled grader when using 10x magnification.
Included or I1/I2/I3 :
Inclusions are noticeable under 10x magnification and may influence transparency and brilliance.