106 Years Since Tolkowsky Invented The "Round" Diamond Cut

Today, Antwerp, Belgium, known as the "Diamond Capital of the World," celebrates 106 years since Belgian engineer Marcel Tolkowsky invented the ideal round brilliant cut for diamonds. In 1919, Tolkowsky published his famous book, "Diamond Design," in which he first presented precise mathematical calculations that determined the ideal dimensions and angles for cutting round diamonds to maximize their brilliance and sparkle.

Tolkowsky is a name best known for the round brilliant cut, the most sought-after diamond shape in the world. A pioneer in diamond design, Tolkowsky established the ideal proportions for round brilliant diamonds in 1919 to maximize their brilliance and sparkle.

What is a round brilliant diamond?

It is the most popular diamond shape, consisting of 57-58 facets and offering a distinctive brilliance and sparkle. This design, which consists of 57 facets, is considered the gold standard in the diamond industry, ensuring maximum light reflection within the stone, giving it an exceptional brilliance. Many gemological institutes, such as the Gemological Institute of America (GIA), have adopted it as the basis for evaluating cut quality.

Marcel Tolkowsky?

Marcel Tolkowsky was born on December 25, 1899, in Antwerp, Belgium, to a Jewish family of Polish origin known for their expertise in diamond cutting. He studied engineering at the University of London, where he completed his postgraduate studies in the field of light and reflection. In 1919, he published his famous book, Diamond Design, in which he presented the first mathematical model for perfect diamond cutting.

Significance of His Invention: The Ideal Brilliant Cut

Tolkowski is considered the founder of the "Ideal Round Brilliant Cut," also known as the American Cut or the Tolkowski Cut. His design was based on precise mathematical calculations of the diamond's dimensions and angles, with the goal of maximizing light reflection within the stone for maximum brilliance and radiance.

The key specifications of his ideal cut include:

Total Depth: 59.3%

Crown Angle (Apex): 34.5°

Pavilion Angle (Bottom): 40.75°

Table Diameter: 53%

Girdle Limit: 0 (in the original design, although this is impractical in practice).

In 2019, the Antwerp Diamond Exchange (AWDC) held a special celebration on the city streets to mark the centenary of the invention. Fifty-seven Antwerp residents, from diverse cultural and social backgrounds, were invited to participate in the polishing of a single diamond, with each person polishing one facet. The project was named "100 Years of Brilliance," marking a century since Tolkowsky's creation.

The polished stone was displayed at the Deva Diamond Museum in Antwerp, a testament to Tolkowsky's legacy and ongoing influence on the diamond industry. Gabi Tolkowsky, one of the world's most renowned diamond cutters, who polished the first facet of the stone, participated in the celebration. Gabi Tolkowsky passed away in May 2023, at the age of 84.

These celebrations affirm Antwerp's continued leadership in the global diamond industry and the importance of innovation and diversity in preserving this precious legacy.

Marcel Tolkowsky died on February 10, 1991, at the age of 91. His design for the perfect brilliant cut remains a recognized standard in the diamond industry, used as a basis for evaluating cut quality in laboratories and factories around the world.