What is the secret behind creating the perfect sparkling diamond or ideal cut diamond? Since time unknown, diamond cutters from various corners have had an obsessive concern for precision, to implement the exact angles and proportions that can maximise the brilliance and fire of a diamond. It was in the year 1919, that Marcel Tolkowsky a Belgian mathematician and diamond polisher unveiled the most accurate diamond model termed the “ideal cut”. It carries the ultimate formula for perfection. Using a two-dimensional model of a diamond, Tolkowsky calculated that with a 16.2 percent crown height, a 53 percent table, a 43.1 percent pavilion depth, a knife-edge girdle and no culet, the ultimate balance of light dispersion and brilliance can be achieved, thus was born the modern brilliant cut diamond.
Since then various changes were incorporated and the figures have been increased to include a 57.5 percent table and other features such as accurate angles for pavilion depth and crown height. It has also been identified that there is no single accurate point at which a diamond is termed “ideal” rather a set of proportion standards that a diamond will be required to be within all aspects to achieve a ideal cut grading.
Importance of an ideal Diamond Cut:
A diamond’s cut is the most important contributor to the allure and the brilliance of a diamond. Only an ideal cut diamond can produce the maximum sparkle, brilliance and liveliness through refracting all of the light that enters the diamond back out of the crown of the diamond with perfect symmetry. All diamonds even poorly cut will still sparkle but the importance of creating an ideal cut diamond is to have as near to 100% light refraction form the cut of the diamond.
When a diamond is termed as an ideal cut, it no longer means the original mathematical shape created by Tolkowsky of the cut but more a general statement for all shapes. Meaning that the diamond has been cut to the most perfect proportions for that shape for light to enter the stone, reflects from one side to the other and bouncing as near to 100% of the light back out of the table and towards you. This phenomenon is termed as “light return” and is directly related to the diamond’s brilliance, brightness and dispersion. The greatest assurance that you are purchasing an ideal cut diamond is to purchase a diamond that is internationally certified.
Ideal Cut Certified diamonds
To accurately assess a diamond for an ideal cut requires the skill and equipment of a certification laboratory. To measure the light refractive index and critical angles of a diamond requires more than just the skills of a certified diamond grader with a loup and must be sent to an internationally recognized diamond grading laboratory.
A trained diamond grader assesses the quality of the diamond as well as the symmetry and proportions of the diamond and evaluates the diamond’s overall cut grade based on the “ideal” cut standards as its benchmark. All factory are measured and considered when grading a diamond and to be termed as “Ideal” the diamond must pass all of the requirements of craftsmanship, proportion and light performance to achieve perfection. There is no one standard grading process, but the diamonds graded by GIA and AGS are widely followed and accepted as the superior provider for the industry world wide.
GIA follows a cut grade system that runs as Excellent, Very Good, Good, Fair and Poor. GIA does not have any cut that is termed “ideal”. An ideal cut diamond by GIA is generally termed as a Triple Excellent and is the highest cut grade obtainable. The cut grade of AGS runs as Ideal, Excellent, Very Good, Good, Fair and Poor. The ideal cut grade is based on the AGS’s standard requirements of perfect proportions, symmetry and polish. They are basically recognised in the diamond industry as “triple-zero” grade. The ideal cut of AGS is equivalent to the Excellent cut grade of GIA.