Of all the 4C’s of the diamond, the cut is considered the most important factor, as its proportions determine how light is reflected by the stone. A proportioned cut will let the light traverse through the diamond in such a way that it will be reflected back to the viewer’s eye and give a boost to the other 4Cs. To check the quality of some certain Diamond’s cut is obtained by its grading or the measurement of a diamond’s dimensions.

A well-cut diamond reflects more light and appears larger than its actual size. It also makes the face-up color looks brighter, and at the same time minimizes its inclusions. This happens because a well-cut diamond has greater brilliance, fire, and luster which easily conceals all the flaws and inclusions.

How to check the quality of a Diamond’s cut

The easiest way to figure out the quality of a diamond’s cut is to look at its grade and the grading certificates of the stone.

The cut of a diamond is evaluated by the following grades:


Very poor



Very good


Cut grades best determine the quality of round stone diamonds.

Brilliant cuts, such as the princess cut, and the round cut, are designed in a way to emit most of its sparkle. So, It is the perfect parameter to judge how well-cut stone is.

When one of the two diamonds with the same cut has the more shine and sparkle, it’s more likely to have a higher-quality cut.

Checking the dimensions and proportions of a diamond cut:

The most accurate way to examine the quality of the cut of a stone is to keep its key Measurements in mind.

Let’s look at some terms familiar with measuring and evaluating a diamond’s cut

Culet: The ideal culet is considered very tiny, big and medium culets are not that high in demand.culets are something you will find at the very bottom of the diamond. Some of the stone can be with no culets too

Girdle. The outer edge of the stone is girdle. The percentage of the girdle’s diameter determines the diamond proportions. Girdles are graded on the basis of its thickness, Cuts that have extremely thick or extreme thin girdles are not in demand. The ideal girdle is between too thick and too thin. It should be thin to slightly thick.

Percentage of table

The topmost facet of the stone in the table. Its percentage can be obtained by dividing the table diameter or width by the diameter or width of the girdle.

Percentage of depth

The distance obtained from the table to the bottom of the stone when divided by the girdle diameter or width.

Round cut proportions

A round cut is graded good when they usually have tables in the 52%-53% and 58%-60% ranges. Those with a value below 51% or above 64% comes under the range of fair and poor cuts. The total depth ratio should be ranging between 57.5%-59.5%.

The proportions of different cuts

The ideal table cut percentage for all the cuts like Oval cut, Marquise cut, Pear cut, and Heart cut ranges between 52%-64 %. The lower value as 51% or higher as 68% is also good. Cuts that come with a percentage of less than 50% and lower than 69% are of considerably low quality.

The ideal percentage for the oval cut is between 58%-60%. The depth percentages that come under the range below 53% or above 70% is not at all a perfect fit.

Here is the ideal length to width ratio for the different cuts:

  • Oval: Ranging between 1.25 and 1.60, best in the 1.30-1.50.
  • Marquise: Between 1.65 and 2.30 ideally in the 1.85-2.00
  • Pear-shaped: Between 1.35 and 1.80, best between 1.40-and 1.55.
  • Heart-shaped: Between 0.80-1.10; ideally between 0.90 and 1.05.

Emerald and Asscher cut proportions

The Asscher cut is a square-shaped cut. The emerald and the Asscher cut is almost the same.

A table- percentage ranging between 60-70%is considered accurate for these cuts. And Percentage below 55% or higher than 75% are figured best. Those Emerald and Asscher cut whose percentage ranges lower than 54% and higher than 74% should not be taken into consideration. To check the quality of some specific Diamond’s cut is obtained by its evaluating or the estimation of an Emerald and Asscher cut proportions measurements.

The percentage of depth should be ranging between 60%-70. Those with lower percentage values like 50% or higher value like 74% are not at all recommended.

For the cuts like emerald cuts, the most sought after length to width ratios comes under 1.20-1.80 range. Whereas for an Asscher cut, the accurate length to width ratio ranges between 1.00 and 1.05.

Cushion cut proportions

The accurate table percentage for a. cushion cut proportion comes between 58% and 70%.

The recommended depth percentage value for it is generally; 58%-70% range.

The length to width ratio for a non-square cushion cut diamond falls under the range of 1.10-1.30.

Radiant cut proportions

Table percentage of a good lustrous diamond falls under the range of 60%-70%. The table percentage exceeding this is not good. The ideal depth percentage for this is 60%-70%.

The recommended length to width ratio for non-square radiants is in the 1.10-1.40 range.

 So, why do poor cut diamonds are preferred?

We buy diamonds for its scintillating charm, radiance, and brilliance. So, why would anybody want such a diamond that would be deprived of all these properties.?

1. Many people prefer the carat weight than the shine and luster.

2. The prices sharply increase for bigger carat weight than for a better cut. Many diamond cutters intent to preserve weight during the process of cutting.

3. More weight will be hidden in the diamond if a cutter produces a deeply cut diamond. It drives the carat weight and increases the price too.

4. The diamond cutters hardly want to eliminate the inclusions present in the diamonds as they want to preserve more weight, they would rather go for a little low quality in order to increase its weight.

Besides wealth and health, learning, teaching, and cooking are my interests in life. I have a bachelors in engineering and an unbeatable streak of optimism, come what may! I love to learn new things! Hope you do too.

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