Diamond clarity (GIA)
Eleven grades from Flawless to Included, all assessed under 10x magnification. Most diamonds in retail jewellery fall between VS and SI — and at those grades the inclusions are usually invisible without a loupe.
| Property | Value | Authority |
|---|---|---|
| Scale range | Flawless (FL) to Included (I3) [1] | — |
| Number of grades | 11 [1] | — |
| What it measures | The number, size, relief, nature and location of clarity characteristics — inclusions internally and blemishes on the surface. [1] | — |
| Applies to | Diamonds. [1] | — |
| Viewing condition | 10x magnification. Every diamond is evaluated under 10x and assigned a grade. [1] Many characteristics that determine the grade are not visible to the naked eye at all. | — |
| Grades in full | Flawless (FL) — no inclusions and no blemishes visible. Internally Flawless (IF) — no inclusions visible, but blemishes present. Very, Very Slightly Included (VVS1, VVS2) — inclusions so slight they are difficult for a skilled grader to see. Very Slightly Included (VS1, VS2) — inclusions observed with effort, characterised as minor. Slightly Included (SI1, SI2) — inclusions are noticeable. Included (I1, I2, I3) — inclusions are obvious and may affect transparency, brilliance and durability. [1] GIA notes that most diamonds seen in jewellery stores fall between VS and SI. | — |
Sources
- GIA — Diamond Clarity — Gemological Institute of America (GIA 4Cs, Diamond Clarity)