Preferred specs "cheat sheet" (for rounds)

[Dee*Jay]

I have a friend who is starting to look around at stones and I wanted to give her the "cheat sheet" for rounds but I can''t find it (senility at 37 is a terrible thing... )

Depth
Table
Crown and pavillion angles
Etc...

Thank you!

 

[Lorelei]

Date: 6/25/2008 12:08:13 PM
Author:Dee*Jay
I have a friend who is starting to look around at stones and I wanted to give her the ''cheat sheet'' for rounds but I can''t find it (senility at 37 is a terrible thing... )

Depth
Table
Crown and pavillion angles
Etc...

Thank you!

Here you go!

depth - 60 - 62% - although my personal preference is to 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

note - 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 - check as appropriate!

 

[Dee*Jay]

Thank you!!

 

[Ellen]

For GIA stones, JohnQ posted this once, should help.


As the above implies, configurations depend on each other. A little give here can still work with a little take there.

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).

 

[Lorelei]

Date: 6/25/2008 12:57:36 PM
Author: Ellen
For GIA stones, JohnQ posted this once, should help.


As the above implies, configurations depend on each other. A little give here can still work with a little take there.

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).

Good addition, couldn''t remember where to find that!

 

[Ellen]

Fanks, I bookmarked that one long ago.

https://www.pricescope.com/community/threads/help-i-think-i-have-been-taken.55849/page-2

 

[Lorelei]

Date: 6/25/2008 1:08:57 PM
Author: Ellen
Fanks, I bookmarked that one long ago.

https://www.pricescope.com/community/threads/help-i-think-i-have-been-taken.55849/page-2

*marking*

 

[oldminer]

Here is the parametric chart from the AGA Cut Class system. This is a good screening tool.