Diamonds are all created organically, deep within the earth, under intense heat and pressure, and each one is different. They each have their own unique characteristics, and in many cases that includes slight imperfections. When these imperfections are inside the diamond, they are referred to as inclusions. When they are on the diamond surface, they are referred to as blemishes. A diamond's clarity refers to the level of these imperfections. The more imperfections, the less brilliance, as light passing through the stone reflects against the imperfections, interfering with the brilliance. The locations of inclusions affect how much the diamond's brilliance is affected, so diamond cutters try to cut stones to minimize the affect of the inclusions on the diamond's brilliance. Inclusions occurring under the bezel facets or near the girdle have less of an affect on brilliance, so the diamond cutter tends to cut the stone to position any inclusions in these locations. Almost all diamond grading is done for clarity using the 11 point diamond clarity scale created by the GIA. In grading diamonds clarity, the GIA considers the number, size, color, reflectivity, and position of every flaw visible under 10x magnification.
GIA DIAMOND CLARITY SCALE1. Flawless (FL) – No inclusions or blemishes are visible to a skilled grader using 10× magnification 2. Internally Flawless (IF) – No inclusions and only blemishes are visible to a skilled grader using 10× magnification 3. Very, Very Slightly Included (VVS1 and VVS2) – Inclusions are difficult for a skilled grader to see under 10× magnification 4. Very Slightly Included (VS1 and VS2) – Inclusions are clearly visible under 10× magnification but can be characterized as minor 5. Slightly Included (SI1 and SI2) – Inclusions are noticeable to a skilled grader using 10× magnification 6. Included (I1, I2, and I3) – Inclusions are obvious under 10× magnification and may affect transparency and brilliance