Types of Round Brilliant Cut

You might not be aware that a well cut diamond reflects more light and looks more beautiful than a diamond with comparatively higher clarity and better color shade.

There are various forms of diamond cuts, but the modern Round Brilliant cut is the most popular among diamond cuts. Over the period of time, facets arrangements and cut proportions have evolved and famous cutters have given cutting variations in modern round brilliant cut. These cuts are:

  • Tolkowsky Brilliant Cut
  • Ideal Brilliant Cut
  • Practical Fine Cut
  • Parker Brilliant Cut
  • Scan D.N. Standard Brilliant Cut
  • Eulitz Brilliant Cut

So, let’s talk about these in more detail.

Tolkowsky Brilliant Cut

This cut was developed by Belgian diamond cutter Marcel Tolkowsky in 1919. It is also known as American Ideal or Tolkowsky Brilliant. In America, this cut is considered as benchmark and basis of cut grading.

In this cut, both the brilliance and fire of diamond is considered which is derived on the basis of mathematical calculations.

The measurements of this cut are:

Proportion of Crown Height to Girdle Diameter 16.2%
Proportion of Pavilion Depth to Girdle Diameter 43.1%
Proportion of Table Diameter to Girdle Diameter 53%
Crown Angle 34.5o
Pavilion Angle 40.75o

Ideal Brilliant Cut

It was developed by Johnson and Roesch in 1929. This cut takes into consideration only the light falling perpendicularly on the diamond. Light entering slant wise is not taken into consideration. Thus, the brilliance of this cut is limited.

The measurements of this cut are:

Proportion of Crown Height to Girdle Diameter 19.2%
Proportion of Pavilion Depth to Girdle Diameter 40%
Proportion of Table Diameter to Girdle Diameter 56.1%
Crown Angle 41.1o
Pavilion Angle 38.7o

Practical Fine Cut

This cut was developed in Germany by Eppler in 1939. It’s also called Feinschliff der Praxis and Eppler cut. This cut was developed as a result of practical experience and practical observation thus named Practical Fine Cut.

Practical Fine cut is set as benchmark in Germany and other European countries and used as standard cut for judging cut proportions. This cut takes into consideration both perpendicularly and slant-wise entering light. It differs from Ideal Brilliant cut to great extent but it has improvised on Tolkowsky cut.

The measurements of this cut are:

Proportion of Crown Height to Girdle Diameter 14.4%
Proportion of Pavilion Depth to Girdle Diameter 43.2%
Proportion of Table Diameter to Girdle Diameter 56%
Crown Angle 32.2o
Pavilion Angle 40.8o

Parker Brilliant Cut

This cut was developed in 1951 by Mr. Parker. Its cut proportions results in very low brilliance as the crown is too shallow. Therefore, this cut hasn’t gained much popularity. The measurements of this cut are:

Proportion of Crown Height to Girdle Diameter 10.5%
Proportion of Pavilion Depth to Girdle Diameter 43.4%
Proportion of Table Diameter to Girdle Diameter 55.9%
Crown Angle 25.5o
Pavilion Angle 40.9o

Scan D.N. Standard Brilliant Cut

The Scan D.N or Scandinavian Diamond Nomenclature was developed in 1969. The proportions of this cut were developed on the basis of observation and practice.

The measurements of this cut are:

Proportion of Crown Height to Girdle Diameter 14.6%
Proportion of Pavilion Depth to Girdle Diameter 43.1%
Proportion of Table Diameter to Girdle Diameter 57.5%
Crown Angle 34.5o
Pavilion Angle 40.75o

Eulitz Brilliant

This cut was developed by Mr. W.R Eulitz in the year 1972. This is the only cut that gives emphasis to the girdle thickness.

Mr. Eulitz in his work “Determining mathematically the optimum brilliance of brilliants”, showed mathematically that maximum of light yield resulting from internal total reflection and an optical color scattering from dispersion can be obtained by using the proportions given by him. These proportions are very close to that given in Eppler or Practical Fine Cut.

The measurements of this cut are:

Proportion of Crown Height to Girdle Diameter 14.45%
Proportion of Pavilion Depth to Girdle Diameter 43.15%
Proportion of Table Diameter to Girdle Diameter 56.5%
Crown Angle 33.36o
Pavilion Angle 40.48o

Return from Types of Round Brilliant Cut to Cuts of Diamond page

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