Diamond Cut Part 2: Crown and Pavilion Angles
In part one of this series we discussed how the Table and Depth Percentage effect the cut of a diamond.
In part of two, we'll take a look at the last two important factors of cut, the crown and pavilion angles, to give you a better idea of what you should be looking for when you purchase a diamond.
The relationship between the crown angle and the pavilion angle has the greatest effect on the appearance of any diamond. A slightly steep pavilion angle can be complemented by a shallower crown angle, and vice versa.
Diamond Cut Part 1: Table and Depth Percentage
Different aspects of a diamond
The cut of a diamond determines how well the stone reflects light. This reflection is responsible for the gem’s brilliance or overall sparkle. There are many aspects to a stone which contribute to angles and the cut form, as the diagram to the left indicates.
Diameter: The width of the diamond through the girdle.
Table: The largest facet at the top.
Crown: The Top part from the girdle to the table.
Girdle: The narrow band around the widest part.
Pavilion: The bottom part from the girdle to the cutlet.
Culet: The facet at the bottom tip. The preferred cutlet is not visible to the naked eye.
Depth: The height from the cutlet to the table.
Professional and skilled cutters cut the stone to mathematically precise proportions to allow as much light as possible to reflect from each of its mirror-like facets out of the top of the diamond.
What are ideal diamond proportions?
Single example of Tolkowsky’s Theorem's predicted proportions.
Proportions determine a diamond's brilliance (the amount of light reflected back to your eye), fire (the flashes of colour due to prismatic separation into the colours of the rainbow) and scintillation (sparkling movement of light as you move the diamond). If ideal proportions are used in the creation of diamonds, their overall excellence can be optimised.
In 1919 Marcel Tolkowsky was responsible for discovering the basis of what is now regarded as the “Ideal Cut” diamond. The Mathematician formed a Masters thesis on the proportions for round brilliant cut diamonds.
Supposedly, he conducted his research by asking Londoners to select the most appealing diamond from a small group. He combined these observations with those of his family’s Belgian diamond cutter business and then applied maths and physics to confirm why certain proportions produced the best looking diamonds.
The image shows a single example; in fact Tolkowsky’s theorem predicted a range of proportions with varying combinations of pavilion and crown angles that could enhance brilliance and fire. A variation on this was the Eulitz cut, developed in 1972 and considered to be ‘mathematically perfect’.
Follow Us!
Recent Posts
- What is an ‘eye clean’ diamond?
- Famous Pink Diamonds of the World
- Famous Yellow Diamonds of the World
- Famous Blue Diamonds of the World
- Top Celebrity Engagement Rings: Part Two
Categories
Useful Links
77Diamonds Twitter Feed
- Gifted jewels from one of the 20th century's greatest love stories to be auctioned in November! http://bit.ly/9pXssD
- @lasvegascut Cheers for the RT and #FF !
- @WishpotWedding @TrulyHeidi Cheers for the #WW :)