Marcel Tolkowsky was a Belgium diamond cutter, In 1919 he publicized his determinations for the most attractive and balanced cut for round brilliant diamonds, his proportions where based on experience, maximum beauty, collected opinion and mathematical calculation, this set the industry standard for many years, Marcel could be described as the father of the Modern Brilliant cut.
His proportions for cutting were followed and approximated for many years.
Diamonds are some times improperly called Tolkowsky cuts when their proportions range only approximates that of the exact proportions determined by Tolkowsky.
These proportions are
- 34.5° Crown Angle.
- 40.75° Pavilion Angles.
- 59.3% Total Depth (excluding girdle thickness) with 16.2% of the depth being comprised of the crown (top half of the diamond) and 43.1% representing the pavilion lower half of the diamond.
- 53% Table based on diamond's overall diameter.
Now with increased desire for perfection and with greater beauty the Hearts and Arrows Ideal Cut Diamond was created too even more exacting proportions of balance and beauty , remembering that only an exact small changeable ratio of proportions creates this Phenomenon of the Hearts and Arrows effect.
The American Gem Society or AGS has laid down their determination Ranges for Ideal Brilliant Cut Diamonds. The Tables are as follows:
