Diamond Clarity: The term "diamond clarity" refers to the number, position and size of the inclusions that occur naturally inside the diamond. The fewer and less obvious the inclusions, the more valuable the diamond. Internal characteristics are called inclusions. The most common inclusions are crystals, clouds, and feathers. Crystals are minerals trapped inside a diamond. Clouds are hazy areas typically created by crystals too tiny to see under 10x magnification. Feathers are breaks in a stone.

The diamond grades are as follows:

F: Flawless. The diamond shows no inclusions or blemishes of any sort under 10X magnification when observed by an experienced grader. Note: Truly flawless or internally flawless (F or IF on the GIA as grading scale) diamonds are extremely rare.

IF: Internally Flawless. The diamond has no inclusions when examined by an experienced grader using 10X magnification, but will have some minor blemishes.

VVS1 / VVS2: Very, Very slightly included. The diamond contains minute inclusions that are difficult even for experienced graders to see under 10X magnification.

VS1 / VS2: Very slightly included. The diamond contains minute inclusions such as small crystals, clouds or feathers when observed with effort under 10X magnification.

SI1 / SI2 / SI3: Slightly included. The diamond contains inclusions (clouds, included crystals, knots, cavities, and feathers) that are noticeable to an experienced grader under 10X magnification, but are generally not noticeable by the naked eye.

SI1 / SI2 / SI3: Included. The diamond contains inclusions (possibly large feathers or large included crystals) that are obvious under 10X magnification and may affect transparency and brilliance.

Diamond clarity is graded using ten-power (10x) magnification, as most inclusions are invisible to the unaided eye. Type, position, and size of inclusions are crucial to determining clarity. Inclusions in the table, the heart of the stone, will significantly downgrade a diamond's clarity.