You are at : Site Map > Education and Guidance > Understanding Diamonds > Diamond Clarity Diamond Clarity The highest grade of diamond clarity is a clear or ‘flawless’ diamond. The 'flawless' diamond is most sought after and deemed ‘extremely rare’. In the 1950's the Gemological Institute of America developed a diamond clarity grading scale which had nine grades. This scale is now recognised as the standard for grading diamonds today. Clarity relates to the existence of the internal and external characteristics of a diamond. These characteristics are often referred to as inclusions or birth marks which appear within or on the surface of the diamond. Inclusions may be crystals, foreign material or structural imperfections that appear as tiny cracks. The number, size, location and visibility all affect the ability of light to pass into and out of the diamond freely, therefore affecting the brilliance. The illustration below gives an example of the inclusions or birth marks that can be seen within the stone under a 10x magnification and also the GIA term for the diamond clarity. Diamond Clarity Grading Table The following grading table gives the official GIA grade, description and comments on the various diamond clarity grades. Grade Description Comments FL Flawless No internal flaws or external flaws on the stone. Extremely rare diamond IF Internally Flawless No internal flaws but 1 or 2 very small surface flaws, undetectable to naked eye. Extremely rare diamond VVS1 Very, Very Slightly Included Very difficult to see marks under 10x magnification. An excellent and rare diamond VVS2 Very, Very Slightly Included Very difficult to see marks under 10x magnification. An excellent and rare diamond (1 or 2 more than VVS1) VS1 Very Slightly Included Inclusions not visible to the naked eye VS2 Very Slightly Included Inclusions not visible to the naked eye (1 or 2 more than VS1) SI1 Slightly Included Inclusions visible under 10x magnification. Maybe visible to naked eye SI1 Slightly Included Inclusions visible under 10x magnification. Maybe visible to naked eye SI2 Slightly Included Inclusions visible under 10x magnification. Maybe visible to naked eye (1 or 2 more than SI1) I1 / I2 / I3 Included Marks visible with naked eye Ralph Blacklock only offers for sale diamonds with clarity grades of FL-Flawless and VS1, click here to read more about our diamond quality. [ Diamond Colour ] [ Diamond Clarity ] [ Diamond Cut ] [ Diamond Carat Weight ] [ Diamond Certification ] [ Diamond Shape ] [ Diamond Care ] [ Diamond FAQ ]