4 Cs of Diamonds


Clarity describes the clearness or purity of a diamond. This is determined by the number, size, nature, and location of the internal (inclusions) and external (blemishes) imperfections.

Diamond Education Clarity:

Symbol Meaning Definition
F Flawless Free from all inclusions or blemishes.
IF Internally Flawless No inclusions visible at 10x magnification.
VVS1 Very Very Slightly Included #1 Inclusions that are extremely difficult to locate at 10x.
VVS2 Very Very Slightly Included #2 Inclusions that are very difficult to locate at 10x.
VS1 Very Slightly Included #1 Minor inclusions that are difficult to locate at 10x.
VS2 Very Slightly Included #2 Minor inclusions that are somewhat difficult to locate at 10x.
SI1 Slightly Included #1 Noticeable inclusions that are easy to locate at 10x.
SI2 Slightly Included #2 Noticeable inclusion that are very easy to locate at 10x.
I1 Included #1 Obvious inclusions. Somewhat easy to locate with the unaided eye.
I2 Included #2 Obvious inclusions. Easy to locate with the unaided eye.
I3 Included #3 Obvious inclusions. Very easy to locate with the unaided eye.

Cut refers to the proportions, finish, symmetry, and polish of the diamond. These factors determine the fire and brilliance of a diamond. Well cut diamonds sell at a premium and poorly cut diamonds sell at discounted prices. With the advent of technology, the cut of the diamond can be determined through the use of the Dia-Mension system, a computerized system which takes accurate measurements and proportions of a diamond in seconds, in addition to the standard millimeter gauge.

As an example, a round brilliant cut, which has 58 facets, is shown below. Since the quality of the cut is directly responsible for the stone’s beauty, the precision with which the facets are arranged is of prime importance. They determine the amount of light reflected to the eye, called brilliance.

Diamond Education Cut:

The proportions displayed by the stone are very significant. Two of the key factors in the grading of cut quality — table percentage and depth percentage — are usually expressed on grading reports. Measurement of three different parameters allows for easy calculation of these percentages by using the formulas expressed below.

  “Premium Cut” “Tolkowsky Ideal Cut” “Excellent Ideal Cut”
Total Depth 58.8% – 63.8% 58.0% – 63.8% 59.2% – 62.4%
Table Size 58.0 – 61.0% 53.0% – 58.0% 52.5% – 58.4%
Crown Height 13.0% – 17.0% 14.2% – 16.2% -
Crown Angle 32.7° – 36.3° 33.7° – 35.8° 32.5° – 35.4°
Pavilion Depth 41.7% – 45.0% 42.2% – 43.8% 41.5% – 44.4%

Diamond Education Carat:

Carat Weight

Carat Weight is the unit of weight for the diamond. A carat is further subdivided in 100 points ( 0.01 carat = l point ). One carat is equal to 0.20 grams. Value per carat increases with carat size, because larger rough diamonds occur less frequently. In other words, 2 half-carat diamonds taken together will not cost as much as 1 one-carat diamond, as the one-carat stone is more rare.

Diamond Education Color:

A diamond's color grade is based on how noticeable the color is, GIA refers to this as the D-Z range, also known as the depth of color. The difference in color grade can have a significant impact on price and appearance.

D-E-F : These grades are considered colorless, D and E diamonds have virtually no color, and an F has a nearly undectable amount of color that shows only in the facedown position. The differences between these grades are actually very slight, in diamonds smaller then .25 ct. they are almost indistinguishable. Diamonds in this color range are extremely rare and valuable.

G-H-I-J : These grades are near-colorless. Diamonds with these grades look colorless face-up and nearly colorless face-down. They might have slight traces of color that aren't noticeable to to the untrained eye when the stone is mounted. * All Sheiban Diamonds are a Grade I or better.

Grades K and below : These Diamonds present from faint to light yellow cast. Once a diamond goes beyond the Z color range it enters the fancy color range starting with Fancy Light Yellow.

GIA'S strict guidelines for each color range make communication about diamond color dependable and accurate. A GIA graded F-color Diamond is an F-Color Diamond, no matter where you are. **Your diamond should always be accompanied by a GIA grading certificate.


The cost of a diamond is what the other 4 C’s determine. Diamond cost is usually the definitive factor in whether or not one will buy a particular diamond.

When buying, it’s a good idea to have a budget in mind before you go shopping. Figure out how much you have to spend and stick to it. You can find something to fit most budgets, once you have a good understanding of the initial 4 C’s and how diamonds are priced.

Once you’ve determined your budget, think about the other 4 C’s of diamonds (cut, color, clarity and carat weight) and figure out which are the most important to you. If the person you’re buying for is looking for something big, you might be able to save some money by getting a lower color rating or clarity rating. If she’s looking for something that will sparkle in any light, put cut and clarity at the top of your list and don’t worry as much about carat weight.

Whatever the situation, don’t be afraid to ask questions, ask to see the diamond with a magnification loop or jewelers microscope, and make sure you see more than one stone before making a final decision.

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