Understanding Carat
Understanding Clarity
Another vital diamond grading characteristic is their clarity. This refers to the number, position and size of the inclusions that occur naturally inside diamonds. The fewer and less obvious the inclusions, the more valuable the diamond. Here is an illustration that shows the clarity grading scale that has been established by the world's foremost authority on diamonds, the Gemological Institute of America ( GIA). Note: Diamonds are shown under 10X magnification):
A diamond's weight is measured in what is known as a 'carat', which is a small unit of measurement equal to 200 milligrams
Carat is not a measure of a diamond's size, since cutting a diamond to different proportions can affect its weight. (The word 'Karat' is used to express the purity of gold, and is not used in relation to diamonds.) Here is a diagram that shows the relative size of various carat weights in a diamond that is cut to the same proportions:
Understanding Clarity
Another vital diamond grading characteristic is their clarity. This refers to the number, position and size of the inclusions that occur naturally inside diamonds. The fewer and less obvious the inclusions, the more valuable the diamond. Here is an illustration that shows the clarity grading scale that has been established by the world's foremost authority on diamonds, the Gemological Institute of America ( GIA). Note: Diamonds are shown under 10X magnification):
GRADE AND DESCRIPTION
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's 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 Slightly included. Inclusions are obvious under 10x magnification and may or may not be visible to the naked eye. However, when set in jewelry, the inclusions may become less visible.
I1, I2, I3 Included. Inclusions are obvious under 10x magnification and are usually visible to the naked eye. This quality allows for a larger diamond to be purcha sed at a lower price.
Color
Diamonds with a color grade of D, E or F are considered colorless; G, H, I and J are near colorless; K, L and M have a faint yellow tint; N, O, P, Q and R have a very light yellow tint and S, T, U, V, W, X, Y and Z are light yellow. A diamond that is a D color is absolutely colorless, and is therefore the most valuable.
However, it's important to understand that color alone does not determine the value of a diamond. All '4Cs' must be taken into account. A diamond of D color that has imperfections or is poorly cut is not as valuable as a stone of a lower color grade that has a superior cut and clarity.
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's 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 Slightly included. Inclusions are obvious under 10x magnification and may or may not be visible to the naked eye. However, when set in jewelry, the inclusions may become less visible.
I1, I2, I3 Included. Inclusions are obvious under 10x magnification and are usually visible to the naked eye. This quality allows for a larger diamond to be purcha sed at a lower price.
Color
Diamonds with a color grade of D, E or F are considered colorless; G, H, I and J are near colorless; K, L and M have a faint yellow tint; N, O, P, Q and R have a very light yellow tint and S, T, U, V, W, X, Y and Z are light yellow. A diamond that is a D color is absolutely colorless, and is therefore the most valuable.
