Diamond Inhouse

Why considering the Cut of a diamond the most important?

The Diamond cut is the most important of all the C’s is considered while buying a diamond. Well, it plays a major role in affecting the shine and sparkle of the diamond, and the sparkling feature is on a top priority list for everyone who wants to buy diamonds. The perfect diamond cut can make the diamond sparkle more even with lower color and clarity but the diamond with a weak cut and with better color and clarity will make it look a little less sparkle in the light.

cut of a diamond

What are the main factors impacting the cut of a diamond?

The main factors impacting Diamond Cut Quality are:

Proportions: It includes the ratios and sizes of the diamond’s table, bottom, and height.

Symmetry: It includes the precision of the facets, mirrors, etc.

Polish: It includes the shine and sparkle of the diamond surface.

 Discussing the proportions in detail


Cut of a diamond

Let’s understand the proportions, primarily are its table, bottom, and height in short. These elements are easily understandable and are one of the best indicators to know about diamond quality.

Proportions are the ratios of each diamond facet between its sizes, angles, and shapes. This will help you understand how the diamond will give lasting beauty when it is interacting with the light. 


The diamond table is the flat surface on the top of the diamond. The diamond table plays an important role in the appearance of a diamond. Diamond Table % is determined by dividing the Table Surface area (table diameter as shown in the image above) by the Overall Surface area (girdle diameter as shown in the image above). The Percentage of the table will explain if the % is too high or too low, the light will not travel properly and will make the diamond look dull.

For example, if the table is 4.5mm wide, and the diamond is 5mm wide, table % is considered is 90%.

For the excellent cut grade diamond, the table should be around 54% to 57%. And you can easily locate the table percentage in the certificates provided by any popular Laboratories.



While understanding the bottom, there are many points to be understood which can be difficult for a normal person or not a professional in the diamond field but you can easily locate and understand the following points in any diamond certificates or reports provided by Laboratories. Just mentioning the percentages and angles here for the Ideal cut diamond or Excellent cut diamond.

Pavilion Depth: 42.5% to 44%
Pavilion Angle: 40.5 – 41 degrees



When it comes to height, it is calculated as the distance between the table and the culet. As it might get difficult for the non-professionals, so they can see the table and culet % in any certificate.

From Table to Culet:  54 to 61%.


What is the different diamond cut proportion?

The way the diamonds sparkle or reflect back the light is also because of the different Cut proportions. There can be different types of cut: Ideal cut, Deep cut, and Shallow cut. 

different cuts

What does an Ideal Diamond Cut mean?

The term “ideal diamond cut” is used mainly when any diamond shape with the brilliance in its shape and sparkling feature. In short, the ideal cut has the perfect proportions which make the light travel equally in every facet. This helps in bringing out the brilliance and sparkle the most. The better and more expensive the diamond will be if it is closer to the ideal cut.


What does a Deep cut mean?

Any diamond’s height is too high as compared to its width, this means that the cut of a diamond is too deep, and called a deep cut. In this, there will be some blockage to the light which cannot travel properly in deep cuts to provide that same sparkle that can be found in the ideal cut. So, diamonds with a deep cut will have lower sparkle or will make the diamond look dull as compared to the ideal cut. 

What does a Shallow cut mean?

In this cut, the diamonds are usually made to look bigger. The light comes inside but cannot be able to transfer to the other part and sending it off the diamond. This will make the diamond reduce its brilliance and sparkle. In general, this type of cut of any diamond will reduce its beauty as compared to the ideal cut.

What does Symmetry mean?

Symmetry refers to how diamond size and shape of the facets, table with the culet, etc. are into consideration by the experts. A diamond with poor symmetry will make the sparkle dull and the light travels into the diamond, sending it off at some different angles, which will reduce the brilliance of the diamond.

What does Polishing mean?

Polishing refers to the degree or the percentage of the smoothness of each facet of a diamond which can only be understood by experts. When a diamond comes in the process of cutting and polishing, some tiny defects may be created at the time of polishing. The expert’s knowledge here will help us to find the defects done by polishing on the diamonds.


What are the grades given by the different Labs?

There are many standards created for an ideal cut as we read above like diamond cut along with the diamond polish and symmetry (which requires detailed explanation). We are not going to explore deeper into these terms. Now understand the 5 grades given by one of the trusted laboratories of the world that is GIA.

The G.I.A. (Gemological Institute of America) follows these 5 for giving grades:

Excellent: The diamond is considered an excellent cut as it gives the maximum fire and sparkle and it reflects the maximum light possible.

Very Good: The diamond is considered a very good (VG) cut as it properly reflects most of the light. This is very similar to the excellent cut but a cost-effective one.

Good: The diamond is considered a good cut as it reflects nearly all the light.

Fair: The diamond considers as fair when a little light pass gets out easily without proper reflecting through the bottom and sides of the diamond.

Poor: Poor Cut Diamonds will have no sparkle, brilliance, or fire.

To know and understand the GIA report, you can click here. 

Buying advice for the diamond cut

Remember, the cut is one of the important aspects of how a diamond will look as it affects brilliance and sparkle, which are the main reasons why you buy a diamond in the first place. Do not buy the diamonds without having the knowledge of its cut, the diamond might seem to be very cheap – the cut might be the reason for it. At least, before buying the diamonds, you can ask for the certifications and look at the details of the cut as mentioned above which will guide you.


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