Absolutely perfect natural diamonds are very rare, most of them have so called inclusions. An inclusion is like a small defect inside the stone or on the surface, like a birthmark or fingerprint, and comes from the fact that the diamond was created deep into the earth’s interior under enormous pressure and heat.
The clarity of a diamond is valued based on how many inclusions the diamond has and the size and placing of the inclusions. The valuation is done with a magnifying glass with 10 times magnification since many degrees of inclusions are impossible to see with just the eye.
However, inclusions can affect how the light is refracted inside the diamond, and thus how much the diamond sparkles. Depending on the placements of inclusions they can also make the diamond more sensitive to impact.
The clarity of the diamond is graded on a scale from Flawless (FL) to Included 3 (I3) or Piqué 3 (P3) as it often is called in Europe. The fact that a diamond is Flawless means that there are no inclusions, neither inside the diamond nor on the outside, that can be seen with a magnifying glass with 10 times magnification. On a diamond with the grade Piqué 3, however, you can easily see the inclusions, even with the naked eye.
At Efva Attling Stockholm, we only use diamonds with the rating Very small inclusions (Vs) or better. For diamonds that are less than 0.1 carat, we use diamonds with Small inclusions 1 (SI1 – Small inclusions are divided into two levels, where SI1 is the best). When a diamond is that small, the differences become virtually non-existent between a diamond with Small inclusions and a clearer one. However, it makes a big difference on the final price.
• Flawless (FL): A diamond completely without visible inclusions or defects, even when examined with 10x magnification. It is extremely unusual for a diamond to be rated FL.
• Internally Flawless (IF): A diamond completely without visible inclusions, but with very small blemishes that are only visible to a skilled grader using 10x magnification. It is extremely unusual for a diamond to be rated IF.
• Very, Very Slightly included (VVS1 and VVS2): A diamond with inclusions that are difficult to detect even for a skilled grader, under 10x magnification. VVS1 and VVS2 are also unusual classifications for diamonds.
• Slightly Included (SI1 and SI2): Small inclusions that are easy to detect for a skilled diamond grader, at 10x magnification. On larger diamonds, it is possible to see some of these inclusions with the naked eye.
At Efva Attling Stockholm, we only use diamonds with this classification SI1 if the diamonds are smaller than 0.1 ct. Then the diamond is so small that it is impossible to determine the differences between SI and higher classified diamonds, without advanced special tools.
• Included (I1, I2, and I3) (or Piqué, P1, P2 and P3): Obvious inclusions at 10x magnification. The inclusions can also be possible to see with the naked eye and can also affect the transparency and brilliance.