Diamond Clarity

Almost all diamonds contain minute traces of uncrystallized carbon, called inclusions. Most are not visible to the naked eye and require magnification with a X10 loupe or microscope to be observed. They are the imprint of nature and make each diamond unique. However, the fewer the impurities, the purer the stone and the higher its value.

The size of the impurities and imperfections determine the clarity of a diamond. Diamonds with the fewest and smallest inclusions are assigned the highest clarity grade. Diamond clarity grades are measured by the gemologist under a x10 magnifying glass and are qualified on a scale of IF (Internaly Flawless) to I (Included), with each category having a gemological definition to be read further down on this page in the chapter "how to define the clarity of a diamond? ". To combine the purity criteria with the other criteria (weight, color, cut...), we recommend you to read our article dedicated to Which diamond quality criterion to choose ?

Note that the very high refractive index of light in diamonds and its great power of reflection make most inclusions difficult to see with the naked eye. These small natural defects and inclusions are microscopic and do not alter the beauty and brilliance of the diamond. The presence of inclusions visible to the naked eye is called "pitted diamond" (P).

In 1953, Richard T. Liddicoat and his collaborators established the Gemological Institute of America (GIA) diamond grading system and purity scale. Also known as the Diamond Grading Table, the complete list of diamond grading categories and diamond purity grades is shown below. To purchase a diamond require an independent and recognized certificate (GIA, HRD or IGI) attesting to the purity.

IF - Internally Flawless

In French we say "Pur à la loupe" under x10 magnification. For the purchase of an IF diamond, also require a recognized certificate.

VVS - Very Very Small inclusion(s)

Very difficult to see with a 10X magnifying glass. Position and number of inclusions determine the difference between VVS1 and VVS2. For the purchase of a VVS diamond also require a recognized certificate.

VS - Very Small inclusion(s)

Difficult to find with a 10X magnifying glass. Position and number determine the difference between VS1 and VS2. Require a recognized certificate.

Easily (*) visible with a 10X magnifying glass (* easily... by an experienced professional) and does not affect gloss. SI1 and SI2 represent good purity, above the so-called "commercial" quality generally found in trade. A beautiful S "i" represents an "i "intelligent choice (but not all SI's are equal). Certificate always recommended.
SI3, a "limit" category to be chosen with great discernment "eyes wide open". Choose Si3 "off center".

Five criteria

The third criterion is the location of the impurity. Is it under the table (most visible) and close to a breech? Is it on the side of the stone, under the crown (less visible). This has no impact on the classification of the degree of purity of the stone. Regardless of the location of an inclusion, the evaluation of its degree of purity remains the same. For IF, VVS and VS gemstones, the location of the inclusion does not matter because it is invisible to the naked eye and does not affect the brilliance. But for impurities lower than SI1, this criterion is to be taken into account when buying a diamond: indeed, it is better to have an inclusion hidden under the crown than an inclusion in the middle of the table, more easily visible and more penalizing for the brilliance of the stone. That said, this notion of the location of the inclusion is especially to be taken into account for purities lower than SI1, i.e. for SI2 or Piqué. And to be taken into account for SI1, from the moment the stone weighs more than 0.50 carat. For more information on the location of an inclusion of a stone in our catalog, please do not hesitate to contact us.

Is inclusion internal or external? Diamonds with internal characteristics cannot be classified as flawless or pure under a magnifying glass (IF = internaly flawless). On the gemmology certificate (GIA, IGI and HRD) it is indicated whether the inclusions are internal or external. In the vast majority of cases, they are internal.

Color and relief

The color and relief of the inclusion is primarily a measure of the visibility of an inclusion, or the contrast between the feature and the rest of the diamond. It is better to have an impurity scattered throughout the stone than concentrated in a single point and therefore more pronounced. However, as with the location of the inclusion, this criterion is to be taken into account for impurities of the SI2 and Pitted type. And for impurities of type SI1 for diamonds over 0.50 carat. For IF, VVS and VS, this criterion has very little impact as inclusions are very difficult to see with a magnifying glass and invisible to the naked eye.

To recognize the purity of a diamond, there are 2 methods: learning to examine a diamond with a magnifying glass (which requires training and especially a lot of practice), or learning to read a certificate (which is much simpler). Below, we explain the 3 golden rules to read a certificate:

Check the type of certificate: there are many certificates on the market, but only three of them are worldwide recognized as independent and rigorous by the profession: the GIA, the HRD and the IGI (see link above).

1) We recommend that you rely on only one of these three certificates for the purchase of a certified diamond over 0.30 carat.

2) Verify that the certificate number is engraved on the roundel (circumference) of the diamond. On the certificate is then written: "laserscribed".

3) Understand the diamond purity scale which goes from the best IF to the lowest (Included).

It is not necessary to be a diamond expert or jeweler to be sure that your diamond has the degree of purity you want. It is especially important to be vigilant and to require a GIA, HRD or IGI certificate, then to understand the impact of the degrees of purity in order to choose the purity of your diamond as a connoisseur.

Surface imperfections are called surface defects, and internal defects are called inclusions.

Diamond Dealer Council

The size of the facets (the multiple mirror surfaces on the diamond) increases as the carat weight of the diamond increases. The larger the diamond, the more inclusions are easily visible. Remember to prioritize a higher degree of clarity as your diamond increases in size.

Jeweller's Council

If for budgetary reasons you choose a diamond with fairly large inclusions of the SI2 or Pique type, then be sure to ask for the location of the inclusions. Prefer a diamond whose inclusions are on the sides of the stone, and can be partially if not completely hidden at the time of setting, under the claws of the gold or platinum jewel and which come to set the stone.

Buying a diamond, symbol of purity

The symbolic value of a diamond is strong. The choice of a diamond goes beyond purely rational criteria. If you are very demanding on quality, we strongly recommend that you opt for IF or VVS purity. These are in fact the purities offered by high jewelry houses.

Choose a diamond with VS2 or SI1 type inclusions, as inclusions are present but very difficult to see with the naked eye and do not alter the brilliance of the stone. Indeed these diamonds are much cheaper than IF and VVS type diamonds, while they are already of a very high degree of purity and without falling into the low purities (SI2 and Pitted) that can be seen with the naked eye and affect the brilliance of the stone.

Tip for buying a diamond with maximum visual effect

If maximizing the volume of the stone is your priority, we suggest that you choose a diamond of SI1 or SI2 purity, which will allow you to optimize the carat weight of your stone. However, it is highly recommended to avoid at all costs the piqués (I1, I2...) because they are very easily seen with the naked eye and strongly alter the brilliance of the diamond. For stones weighing more than 0.50 carat and even more from 1 carat, make sure you know where the inclusion is located if it is of type SI1 or SI2.

For more expert advice, we recommend that you read the page which diamond purity to choose?