Qualifications for Round Diamond

[Chelle0511]

I''m sure this has been discussed numerous times, but I can''t seem to locate the link.

I once came across a link that listed ideal specs for a round diamond - can someone please point me in the correct direction?

I''m looking for the ideal range for:

Depth %
Table %
Crown Angle %
Pavilion Angle %
Culet %

I feel comofrtable with my education of color and clarity...

Also, the reports to request when purchasing from a local, family owned jewelry store.

I am 90% sure I have found a diamond online, however my local jeweler has 3 diamonds that he would like to show me tomorrow.

Thanks again, your wisdom amazes me!

 

[Lorelei]

Hi Chelle,

Did you mean this chart?

http://diamonds.pricescope.com/round.asp

Or the numbers some of us use as a guide to find a well cut round diamond?

 

[Chelle0511]

Thanks Lorelei!!

The numbers you use when purchasing a diamond would be great - that table looks awesome, yet Greek to me

.

Also, what grading reports are acceptable?

 

[kcoursolle]

Here is my personal preferences:
depth: 60-62
table: 54-57
crown/pavillion angles: consistent with an HCA score of under 2

 

[Lorelei]

Date: 3/10/2009 2:47:40 PM
Author: Chelle0511
Thanks Lorelei!!

The numbers you use when purchasing a diamond would be great - that table looks awesome, yet Greek to me

.

Also, what grading reports are acceptable?

Ok no problem, here you go!


Here is a cheat sheet some of us use to find well cut round diamonds.


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!


And from expert John Pollard.
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 complementary 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).

Grading reports;

Usually here most buyers look for AGS or GIA, this link explains more on how the grading labs rank.

http://diamonds.pricescope.com/grading.asp

 

[Rockdiamond]

My advice would be to go look at the diamonds your jeweler is bringing in- without any preconceived notions.
Use your eyes, and see if any of the stones he shows you make your heart sing. If you can get copies of the GIA's for the stones he shows you, you'll get a lot of comments form people here.

Although Lorelei's numbers are accepted by most of the folks here, using them will get you what the folks here like, which is not necessarily what everyone likes best.
So look at the diamonds, and see what you like. Your jeweler may have stones that fall outside the PS ranges, and it's ok if you love one.

The acceptance of GIA and AGSL over any other lab is widespread in the diamond industry. Avoid relying on any other report. This goes for an online purchase as well as one from a local jewelry store.