Symmetry, Polish

[mobay]

Any idea as to how symmetry and polish affect brilliance on a round brilliant ideal cut? Do i need to look for excel/excel or is good/good, sufficient? I realize this is all personal taste and how fat the wallet is but on appearance alone, do you lose a lot of brilliance or sparkle if the polish/symmetry is not excellent, and how low (good/good, or vg/vg) would one want to go?

 

[belle]

polish and symmetry grades don''t directly effect the performance of a diamond. you can however get an idea of how much ''effort'' was put into the cut by looking at the polish and symmetry. cutters don''t stumble into cutting a top performing stone.

 

[koko]

Fred Cuellar (The "Diamond Guy") says "good/good" is fine for polish & symmetry. On pg. 177 of his book "How to Buy a Diamond" (4th ed.), he says "If any salesman tries to imply that just because the symmetry on the lab grading report is good or better means it must be a well-proportioned stone, it''s time to leave." Symmetry, excellent or otherwise, doesn''t infer great proportions or the relationship between crown & pavilion angles.

 

[SeaOats]

Date: 10/7/2005 10:32:04 PM
Author: koko
Fred Cuellar (The ''Diamond Guy'') says ''good/good'' is fine for polish & symmetry. On pg. 177 of his book ''How to Buy a Diamond'' (4th ed.), he says ''If any salesman tries to imply that just because the symmetry on the lab grading report is good or better means it must be a well-proportioned stone, it''s time to leave.'' Symmetry, excellent or otherwise, doesn''t infer great proportions or the relationship between crown & pavilion angles.

I''m not disagreeing with this particular piece of information necessarily, but I would take anything the "Diamond Guy" says with a grain of salt. A BIG grain of salt in most cases.

 

[koko]

I''ve noticed from old threads that Fred''s not a real popular guy around here!!

 

[oldminer]

I''d say that in "most" cases your eyes cannot see a difference from Ex/Ex to Gd/Gd when it comes to polish and symmetry. That does not mean there is no difference, but it is nearly or completely something that the eyes don''t readily see. If you use a device that measures brilliancy, etc, then the device will detect these somewhat invisible differences.

Its a similar situation to the IF clarity versus VVS2 clarity. There are differences, but finely tuned ones that the eyes rarely can detect.

Also, remember that well trained eyes with perfect vision will detect a bit more than untrained eyes or ones with somewhat less than perfect vision.......

Polish and symmetry matter. These grades count in some ways in the quest for perfection and quality. They are just a set of components which we grade in very fine ways and with quite a degree of subjectivity still.

 

[strmrdr]

In perfect light conditions with a RB there might not be much difference just like between an ideal cut diamond and a super-ideal cut diamond.

In extreme light conditons there may be more of a difference.
In some light conditions frozen spit will look good but its the tough light conditions that set the awesome diamonds apart from the so-so ones.

With step cuts like asschers and emeralds it may be more of an issue depending on what facets are affected.