Hi! I’ve been looking at various crown angle combinations of various table sizes on the site. I’m trying to maximize spread with an excellent cut and on the graphs, low crown angles such as 32 with pavilions around 41.4 and a table of 60% still perform excellently. Many sites are advocating for crown angles much higher and pavilion angles no more than 40%. Any thoughts on choosing a lower crown balanced by a steeper pavilion?
The arrows tend to fade out with higher pavilion angles, even within AGS 0 Ideal specs. That’s corroborated by my computer vision analysis. You can find diamonds that show strong arrows with higher pavilion angles, but you’ll have to search more.
Another way to increase spread is to not offset the angles as much Something like 33.5 crown 40.8 pavilion generally has a larger spread and would still show the arrows well.
Yes, 60/32/41.4 would be GIA EX/AGS 0 Ideal. However, weaker arrows reduce scintillation because they reduce the contrast between the light and dark facets (dark facets created by the observer’s shadow). Larger tables and lower crown angles tend to favor brightness over fire because it reduces the prism effect of the crown.
Thanks Joe. Am I correct the 60% table 32.0% crown and 41.4% pavilion angles still qualify for GIA ex/AGS ideal rough calculations. It’s mainly we lose the contrast patterns from the arrows? Is there any benefit from a shallower crown and steeper pavilion? I’ve read a lot of the research and know a lot of cut is balancing brightness, fire, and scintillation. Thanks again. This site has been great.