Last updated on December 27, 2022
Have you ever noticed all else being equal, an eye-clean diamond will appear very similar to a flawless one? Surprisingly, diamond clarity does not impact the stone’s beauty until the inclusions are not very large and dark, numerous or located in the centre of the stone.
What Is Diamond Clarity?

Diamond clarity is one of the main characteristics of a diamond that grades how clean the diamond is from any type of inclusions (internal flaws) and blemishes (external flaws). Although imperfections can not be easily recognized by the naked eye, in most cases, clarity along with colour are what people notice first. Clarity grade has a significant impact on a diamond’s value, meaning the fewer inclusions and blemishes the diamond has, the better its grade and the higher its value.
According to the GIA, diamond clarity is graded on the following scale:
- FL (Flawless) – no inclusions and blemishes visible under 10x magnification;
- IF (Internally Flawless) – no inclusions visible under 10x magnification;
- VVS1, VVS2 (Very Very Slightly Included) – hardly noticeable and very small inclusions visible under a gemological microscope;
- VS1, VS2 (Very Slightly Included) – minor inclusions visible with effort under 10x magnification;
- SI1 and SI2 (Slightly Included) – easily noticeable inclusions under 10x magnification;
- I1, I2 and I3 (Included) – obvious inclusions visible to the naked eye.
How Is Diamond Clarity Evaluated?
Although diamond clarity is graded according to how easy it is to see inclusions and blemishes in a stone, evaluating diamond clarity involves determining the size, number, nature, relief and location of flaws, as well as how these affect the overall appearance of the stone.
- Size – The size of the inclusions directly affects the appearance and level of brilliance and sparkle of a diamond. The bigger the inclusion, the bigger the impact on the diamond’s clarity grade.
- Number – The more inclusions in a diamond, the lower its clarity grade.
- Nature – The nature of inclusions refers to the type of flaws. In case the flaw is located only on the surface of the diamond and has not penetrated it, it is considered a blemish instead of inclusion.
- Relief – Relief refers to how visible is the inclusion in contrast to the host diamond. The higher the relief, the darker the colour of the diamond.
- Location – The location of inclusions refers to where on the diamond the inclusions are. In case the inclusion is located close to the table, the clarity grade will be lower because it is easily noticeable. On the contrary, if the inclusion is close to the girdle, it will be difficult to see. Inclusions found close to the pavilion can reflect, meaning the facets will act as mirrors, and the inclusion will be reflected too.
How to Choose a Diamond Based on Its Clarity

Clarity grades are based on a variety of criteria, which is why determining the right grade requires some judgement. Clarity grading is not an exact science, as there is some variation among the diamonds classified in the same category. For example, one diamond may have 4 visible inclusions, and another might have 7, but they both end up in the same grade. Or a diamond can be at the very low end of the VS2 grade and look like a stone from the very high end of the SI1 grade.
Let’s say you want to buy a VS1 clarity diamond. Ask the jeweller to also show you stones one grade lower (VS2) and look at the clearest one among them. Most likely, these stones will look identical to the naked eye, and you will be satisfied with the appearance of the VS2 diamond. As a general rule, always compare different diamonds of the same clarity grade, one grade higher and one lower.
Always ask for a certificate of the stone you are about to buy. If the diamond does not have a certificate, the jeweller may sell you a stone that is actually at the higher end of a certain clarity grade but looks one grade higher. Needless to say, though the difference may not be visible to the naked eye, it may translate into a noticeable price change. That is why you should never buy diamonds without a grading report issued by a reputable laboratory.
Featured image: Mark S Johnson / Shutterstock