FL-Flawless:
Shows no inclusions or blemishes of any sort under 10 x magnifications when observed by an experienced grader.

IF-Internally Flawless:
Have no inclusions when examined by an experienced grader, but will have some minor blemishes.

VVS¹, VVS² - Very Very Slightly Imperfect:
Contains minute inclusions that are difficult even for experienced graders to see under 10x magnification.

VS¹, VS² - Very Slightly Imperfect:
Contains minute inclusions such as crystals, clouds or feathers when observed with effort under 10x magnification.

SI¹, SI² - Slightly Imperfect:
Contains inclusions such as cavities, knots clouds, feathers and included crystals which are noticeable to an experienced grader.

I¹, I², I³ - Imperfect:
Contains inclusions such as large feathers or large included crystals, which are obvious under a 10x magnification and may affect transparency and brilliance.