The Four C's of Diamonds

The Four C’s are important value factors used to describe and classify diamonds. They stand for: clarity, color, cut, and carat weight. Each factor contributes to its value and rarity. 

Clarity

Clarity refers to a diamond’s relative absence of inclusions and blemishes. Inclusions (internal clarity characteristics) and blemishes (external clarity characteristics) may occur before or after a diamond’s formation. While stones with a higher clarity grade are more valuable and rare, clarity characteristics have their own highlights as well; they make each a diamond truly unique as it’s nearly impossible for two stones to share the same blemishes/inclusions in the same locations. 

When determining a diamond’s clarity grade, there are five discerning factors: the size and quantity of blemishes/inclusions, their location, the contrast between these clarity characteristics and the diamond itself, and lastly, the type of the clarity characteristic and its potential effect on the diamond.

Depending on how a diamond fairs when judged on the above factors, the stone would then fall into one of eleven clarity grades. They are:

• Flawless
• Internally Flawless
• VVS1 and VVS2
• VS1 and VS2
• SI1 and SI2
• I1, 12, 13

To learn more about diamond clarity grade, click here. 

Color

The lack of color in a diamond determines its color grade, which ranges from D-to-Z. As is the case with all the Four C’s, the higher the grade, the more rare and valuable the diamond. 

Diamonds are frequently thought of as colorless stones but in actuality, colorless stones are scarce and the majority of diamonds on the market have hints of yellow or brown.

When talking about color, it’s important to note that the letters on the D-to-Z scale do not describe actual colors, but rather a range of color that’s based on tone (darkness or lightness) and saturation (intensity). Using the combination of tone and saturation, the grader will measure how noticeable color is and issue a color grade. 

*include infographic of color scale*

While D-F is the color range for colorless diamonds, many diamonds in the G-I color range can also appear colorless as well. This is because diamonds are graded table-down so it is possible for diamonds in the G-I color to “face-up” much whiter than their color grade. It also becomes much more difficult for consumers to detect color in the G-I range once the stone is mounted. 

Beyond the M color grade, color can be detected very easily. 

And beyond the color Z, all diamonds will be considered “fancy-colored diamonds”.

To learn more about colored diamonds, click here. 

Cut

Oftentimes, cut and shape are used interchangeably but that is a disservice to this “C” as cut encompasses so much more. It also refers to a diamond’s proportions, polish, and symmetry all of which work together to influence a stone’s brilliance, fire, and scintillation. 

Most diamonds in the market today are one of three styles: brilliant cuts, step-cuts, or hybrids. 

*insert infographic showcasing the shapes under these three styles* 

Proportions

A diamond’s proportions affect its ability to reflect and refract light. A well-cut diamond with good proportions will exhibit excellent brilliance, fire, and scintillation. 

When taking proportion into account, one must look at:

Girdle outline
Table size (table percentage)
Crown angle
Girdle thickness
Pavilion depth percentage (a.k.a pavilion angle)
Total depth percentage
Culet Size
Length-to-width ratio (applicable to fancy shapes)

To learn more about each proportion factor, click here.

Polish

Polish affects the overall look of a diamond, which is why gem cutters have to be extremely careful not to leave marks on a diamond. When evaluating a diamond’s polish, graders will look for things such as: abrasions, nicks, polish lines, scratches, etc. 

Based on the grader’s assessment of the diamond’s polish, they will issue it one of the following cut grades: excellent, very good, good, fair, or poor.

Symmetry

Symmetry refers to the precision of a finished diamond’s shape and placement of its facets. When graders look at symmetry, they look for aspects such as a centered table, balanced and even outline, symmetrically sized and placed facets, etc.

Based on the grader’s assessment of the diamond’s symmetry, they will issue it one of the following cut grades: excellent, very good, good, fair, or poor.

It is important to note that while cut affects all diamonds’ beauty, round brilliants are the only ones assigned a cut grade.

Carat

Carat is used to describe a diamond’s weight, not its size. One carat is equivalent to .200 grams and larger stones are much rarer, which makes it more valuable.

Most of the diamonds used in jewelry are less than 1 carat. On average, miners have to process about a ton of rock in order to yield less than half a carat of rough diamond. Not to mention, rough diamonds must be cut, which causes it to lose even more weight. 

Generally speaking, a higher carat weight would mean greater value. However, that is not always the case because if the other Four C’s are not on the same caliber, it lowers the overall value of the stone. 

This is precisely why one must consider each of the Four C’s when choosing a diamond since they work in harmony to give each diamond a unique and beautiful look.