– Flawless (FL) No inclusions and no blemishes visible under 10x magnification
– Internally Flawless (IF) No inclusions visible under 10x magnification
– Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
– Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterized as minor
– Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification
– Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance