![]() |
![]() ![]() ![]() |
|
| Diamond Jewelry Forums
|
|||
|
| |
||
» Diamond Prices and Grading »
» RockyTalky
» |
|
![]() |
Crown and Pavilion Angles |
![]() |
| P: 10/20/2008 3:51:15 PM | |
tunis Rough Rock Total Posts: 66 Last Post: 12/4/2008 Member Since: 10/3/2008 |
Can someone give me an idea of what the optimal crown and pavilion angles might be? My sense is something on the order of 34-35 for the crown and 40.5-41 for the pavilion but is there such thing as a sweet spot within this sweet zone? Thanks in advance, Tunis
|
| Posted: 10/20/2008 3:51:15 PM | |
![]() |
There are 4 replies to this message. There are 4 replies on this page. |
![]() |
| P: 10/20/2008 3:58:29 PM | |
|
Garry H (Cut Nut) Ideal Rock Total Posts: 11,586 Last Post: 11/25/2009 Member Since: 8/16/2000 |
There is a sweet range. Your approach is grossly misguided by many consumer here. If you like the sweet spot in the midddle of that range then you can very safely add 1/2 a degree to the pavilion if you subtract 2.5 degrees from the crown angle. You can subtract 1/2 a degree and add 2.5 degrees to the crown as loong as the table size is 55% or less. Garry Holloway FGAA DipDT |
| Posted: 10/20/2008 3:58:29 PM | |
| P: 10/20/2008 9:51:18 PM | |
|
amyjokerette Cut Rock Total Posts: 307 Last Post: 9/19/2009 Member Since: 9/5/2008 |
Garry do you know how I can calculate or measure my crown and pavilion angles on my Leo diamond? They are not listed! I dont think they list them on the IGI certs... (sigh) Not that it is a bi deal, I love my diamond... I was just curious if there was a formula or a way to measure it by taking a large photo or something. Sorry to piggyback on this thread. AmyJokerette: Former maul store shopper... newly converted PS perfectionist! |
| Posted: 10/20/2008 9:51:18 PM | |
| P: 10/20/2008 10:22:13 PM | |
|
neatfreak Ideal Rock Total Posts: 13,477 Last Post: 11/24/2009 Member Since: 2/17/2007 |
Garry of course is correct that there are many variations. To be super safe and make it easy, these parameters are good ones to start with: depth - 60 - 62% - although you can allow up to 62.4% table - 54- 57% crown angle - 34- 35 degrees pavilion angle - 40.6- 41 degrees girdle - avoid extremes, look for thin to slightly thick, thin to medium etc polish and symmetry - very good and above with crown and pavilion angles at the shallower ends ( CA 34- PA 40.6) and steeper ( CA 35- PA 41) check to make sure these angles complement in that particular diamond - eyeballs, Idealscope, trusted vendor input (courtesy of Lorelei!)
|
| Posted: 10/20/2008 10:22:13 PM | |
| P: 10/21/2008 7:20:14 AM | |
|
Ellen Ideal Rock Total Posts: 22,894 Last Post: 11/6/2009 Member Since: 1/13/2006 |
Here's a bit of a cheat sheet for GIA stones. "With that said, here's a "Cliff's Notes" for staying near Tolkowsky/ideal angles with GIA reports (their numbers are rounded): A crown angle of 34.0, 34.5 or 35.0 is usually safe with a 40.8 pavilion angle. If pavilion angle = 40.6 lean toward a 34.5-35.0 crown. If pavilion angle = 41 lean toward a 34.0-34.5 crown. GIA "EX" in cut is great at its heart, but it ranges a bit wider than some people prefer, particularly in deep combinations (pavilion > 41 with crown > 35)." ~~~~~~~~~~~~~~~~ |
| Posted: 10/21/2008 7:20:14 AM | |
|
|
Next Page |
| « First time buyer needs advice, is this a good buy? « | » GIA G 2.17 Triple Ex - $17k - Good price? Let me hear it expe... » |
Contact Us | Back Home | Privacy Statement | Forum Agreement | Forum Policies | |
| Ideal BB Version: 0.1.5.4.beta1 | Message forum software powered by the Ideal BB |
Pricescope -
Knowledge -
Diamond Prices -
Tools -
Resources -
About
© 2000-2009 Pricescope. Terms of Use Privacy Policy Disclaimer
forum archives