I1 - Included; contains inclusions (possibly large feathers or large included crystals) that are obvious under 10X magnification and may affect transparency and brilliance.
SI2 - Slightly Included; contains inclusions (clouds, included crystals, knots, and feathers) that are noticeable to an experienced grader under 10X magnification.
SI1 - Slightly Included; contains inclusions (clouds, included crystals, knots, and feathers) that are noticeable to an experienced grader under 10X magnification.
VS2 - Very Slightly Included; contains minute inclusions such as small crystals, clouds, or feathers when observed with effort under 10X magnification.
VS1 - Very Slightly Included; contains minute inclusions such as small crystals, clouds, or feathers when observed with effort under 10X magnification.
VVS2 - Very Very Slightly Included; contains minute inclusions that are difficult even for experienced graders to see under 10X magnification.
VVS1 - Very Very Slightly Included; contains minute inclusions that are difficult even for experienced graders to see under 10X magnification.
IF - Internally Flawless; has no inclusions when examined by an experienced grader using 10X magnification, but will have some minor blemishes.
FL - Flawless; shows no inclusion or blemishes of any sort under 10X magnification when observed by an experienced grader.