Understand all the aspects of the Diamond Clarity Scale, in the second of GIA’s 4Cs Q&A series.
A: Like the color scale, the GIA Clarity Grading System developed because jewelers were using terms that could be misinterpreted, such as “loupe clean” or “piqué.” Today, if you buy a diamond somewhere else in the world, the jeweler will most likely use terms like VVS1 or SI2, even if his or her language is French or Japanese instead of English.
Q: What causes diamond inclusions?
A: Small crystals can become trapped in a diamond when it’s forming. Sometimes as a crystal grows it can develop irregularities in its atomic structure.
Q: How is diamond clarity evaluated?
A: Diamond clarity is graded under standard viewing conditions with 10x magnification. The preliminary GIA grader carefully examines the diamond in order to identify clarity/finish characteristics and evidence of any clarity treatments, such as fracture filling or laser drilling.
A minimum of two GIA graders assign their impression of the diamond’s clarity, polish, and symmetry. Next, they plot the clarity characteristics on the diagram most representative of the diamond’s shape and faceting style.
GIA Clarity Scale
The GIA Clarity Scale has six categories, some of which are divided, for a total of 11 specific grades.
No inclusions and no blemishes are visible to a skilled grader using 10x magnification
INTERNALLY FLAWLESS (IF)
No inclusions and only blemishes are visible to a skilled grader using 10x magnification
VERY, VERY SLIGHTLY INCLUDED (VVS1 AND VVS2)
Minute inclusions that range from extremely difficult to very difficult to see are visible to a skilled grader using 10x magnification
VERY SLIGHTLY INCLUDED (VS1 AND VS2)
Minor inclusions that range from difficult to somewhat easy to see are visible to a skilled grader using 10x magnification
SLIGHTLY INCLUDED (SI1 AND SI2)
Noticeable inclusions that range from easy to very easy to see are visible to a skilled grader using 10x magnification
INCLUDED (I1, I2, AND I3)
Obvious inclusions are visible to a skilled grader using 10x magnification and may affect transparency and brilliance
Clarity diagrams are for reference only and do not reflect true diamond clarity quality grades. Images are not for clarity diamond grading.
Updated: GIA report scales have been updated with the newest scales as of May 2014