Diamond Information Crown
The crown is the section from the girdle to the table. There are 2 measurements to consider when looking at the crown. Firstly, the crown height which is the measurement from the girdle to the table given as a percentage of the overall depth. Secondly , the crown angle which is the angle made between the girdle and the table. The Accredited Gem Appraisers (AGA) state that for a round brilliant cut the crown height percentage must be between 14% and 16.3% and the crown agle to be between 34.3-34.7° for it to be a perfect Ideal cut.
Marcel Tolkowsky was a pioneer in the world of diamonds, and was the first person to present a mathematical analysis of diamond cut. In 1919 he released the 'Diamond Design' , A study of the reflection and refraction of light in a diamond. He concluded that a diamond , having the most perfect fire and brilliance should have a single set of proportions. A diamond with no culet and an extremely thin girdle should have a 53% table, crown angle 34.5° , crown height 16.2% , pavillion angle 40.75° , pavillion depth 43.1% and an overall total depth of 59.3% . One must remember though that Tolkowsky's set of proportions will be different for any diamond that has a culet or a thicker girdle
