Clarity is a very important factor in diamond grading. Diamonds are graded on a clarity scale with FL (flawless), or "loupe clean" being the highest clarity. This means the diamond has the highest degree of purity or freedom from inclusions; some might say even say transparency or cleanness. Inclusions are formed in the crystallizing or forming process of a diamond; they are usually naturally occurring. Some types of inclusions include carbon spots, other minerals, and other crystal inclusions such as garnet. Inclusions may look like fractures, clouds, feathers, stains, bubbles or tiny crystals.
Clarity Grading Chart
Below are the foremost clarity grading scales ranged together with impressions of clarities drawn in top view on diamond diagrams.
|Gemological Institute of America GIA||American Gem Society||Scandinavian SCAN.D.N.||CIBJO Confederation International de la Bijouterie, Joaillerie, Orfevrierie des Diamantes.||HRD Hoge Raad voor Diamant Diamond High Council||Russian < 0.29 ct||Russian > 0.30 ct|
|Main Grades <0.47 carats||Sub grades >>0.47 carats|
|FL (flawless)||0||Loupe clean||FL||Loupe clean Free from inclusions and bearding||Loupe clean. Inclusions that do not exceed 5 micron||1||1|
|VVS1 (very, very slightly included)||VVS||VVS1||VVS (VVS1, VVS2) Very, very small inclusion(s), very hard to find with a 10x loupe||VVS1 - VVS2 Inclusions that are visible through table have average sizes of 12 micron (VVS1), 25 micron (VVS2), larger when visible through other facets||2||2|
|VVS2 (very, very slightly included)||2||VVS2||4|
|VS1 (very slightly included)||3||VS||VS1||VS (VS1, VS2) Very small inclusion(s), which can hardly be found with a 10x loupe||VS1 - VS2 Inclusions that are visible through table have average sizes of 40 micron (VS1), 70 micron (VS2); larger when visible through other facets||4||5|
|VS2 (very slightly included)||4||VS2||5||6|
|SI1 (slightly included)||5||SI||SI1||SI (SI1, SI2) Small inclusion(s), easy to find with a 10x loupe, not seen with the naked eye through the crown side||S1 Inclusions that are visible through table have average sizes of 150 micron||7|
|SI2 (slightly included)||6||SI2||7a|
|I1 (imperfect)||7-8||P||P1||PI (Pique I) Inclusion(s) immediately evident with a 10x loupe, difficult to find with the naked eye through the crown side, not impairing brilliance||P1 Inclusions which are visible through the crown-side have average sizes of 0.5 mm||6||9|
|I2 (imperfect)||9||P2||PII (Pique II) Large and/or numerous inclusion(s), easily visible to the naked eye through the crown side and which slightly reduce(s) brilliance||P2 Inclusions have average sizes of 1.5 mm; they slightly reduce brilliance||7||10|
|I3 (imperfect)||10||P3||PIII (Pique III) Large and/or numerous inclusion(s), very easily visible to the naked eye through the crown side and which reduce(s) brilliance||P3 Inclusions have average sizes of 3 mm or larger; they reduce the brilliance||8-9||11-12|