The Gemological Institute of America (GIA) grades diamond clarity on an 11 point scale ranging from Flawless and Internally Flawless (FL/IF) to Included (I1, I2, I3). These categories are founded upon the ability to see the inclusions under 10x magnification. FL/IF to VS2 categories are referred to by diamond experts as “eye clean” and are the categories of the highest clarity. Diamonds classified as “eye-clean” are considered to have no imperfections visible to the naked eye.
Flawless and Internally Flawless certified diamonds are extremely rare. The difference between the two is that internally flawless diamonds (IF), like the FL, are 100% flawless from the inside but IF diamonds will contain surface graining on the outside. These are not technically considered a flaw, but consist in the only point of differentiation between the extremely rare Flawless and the very rare IF clarity grades. FL or IF diamonds may also be referred to as ‘LC,’ meaning “Loupe Clean.”
Very Very Slightly Included 1: VVS1
A diamond of this clarity grade would have one tiny inclusion that can only be located using a powerful microscope. This clarity grade guarantees that the inclusion is invisible even under a 10x magnification loupe. This clarity grade is almost as rare as the IF clarity and as such is highly regarded although not quite as expensive.
Very Very Slightly Included 2: VVS2
These diamonds would only have two tiny inclusions and consistent with the VVS1 grading only a microscope would identify inclusions. However, expert graders may be able to locate a VVS2 inclusion using a 10x magnification loupe but VVS2 still offer a very high level of clarity and are less expensive price than a VVS1.
Very Slightly Included 1: VS1
VS1 diamonds have one small or a few very tiny inclusions that are not visible to the unaided eye (eye clean) and can only be located, often with difficulty, using a 10x magnification loupe. VS1 clarity diamonds are an excellent choice as they are still eye-clean whilst being less expensive than the VVS categories.
Very Slightly Included 2: VS2
Usually VS2 diamonds have a series of tiny inclusions that like the VS1 grade can only be located using a 10x magnification loupe. VS2 clarity diamonds are an extremely popular as it is the last grade which virtually guarantees an eye clean diamond. In 95% of cases VS2 diamonds are eye clean. Rare exceptions, may include VS2 diamonds on EGL or IGI certificates (extremely rare on IGI) and in certain cases, Emerald and Asscher cut diamonds, which may not always be eye clean, even on GIA certificates. The type of inclusions here would generally be two small inclusions or a series of tiny ones.
Slightly Included 1: SI1
SI1 graded diamonds have two medium or many small inclusions that will almost always be visible to the unaided eye and are easy to locate using a 10x magnification loupe. Depending on how well placed and lightly coloured the inclusions are the stones can appear almost eye clean and therefore SI1 clarity diamonds can offer exceptional value for those wishing to maximise their budget. An SI1 diamond on a GIA, HRD or AGS certificate will in over 50% of cases be eye clean depending on the chosen shape. However, as with the VS2, this grade of diamonds probably won’t be eye clean on Emerald and Asscher cuts, on any certificate.
Slightly Included 2: SI2
SI2 diamonds have a greater number of inclusions that will almost always be visible to the unaided eye. As with the SI1 clarity diamonds, they can offer great value for money and depending on the inclusions it can be possible to find an eye clean stone at a fraction of the price of higher clarity grades.
I1 or lower
These diamonds will always have inclusions clearly visible to the naked eye, even on the strictest certificates, such as those of the GIA. Even though it is still possible for us to source such diamonds upon request, we would recommend choosing SI2 clarity diamonds or above
An “eye-clean” diamond is one that has no imperfections visible to the unaided eye. They offer excellent value, being much less expensive than flawless (FL) or internally flawless (IF) diamonds, which are extremely rare and therefore command a higher price.
Imperfections in diamonds graded Slightly Included (SI) are often not visible to the unaided eye, making them excellent value for money, however the location of the inclusion is important. Therefore, it always advisable to speak to a diamond and jewellery consultant to check that the stone is eye-clean, if you’re considering a diamond of this clarity grade.