Help me pick a diamond?

[LynzeeLeigh]

I'm finally getting an engagement ring soon (we've been 'engaged' for a while, but had just bought a house that needed fixing up so it hasn't been in the cards til now). Since I've had so much time to think about it, I'm really having some trouble deciding on my diamond. The biggest I'm going to be able to go is about .7 carats (about 5.7 mm). If I go with that I'm looking to get at least a G in color, but preferably F and an eye clean SI1 or SI2. If I go a little smaller, like .63 (5.4/5.5 ish mm), I'll be able to get an F or E and VS2 in clarity. OR I could go a little bigger than the .7 but probably have to go down to I in color and stick with an eye clean SI2. No matter what, I'm getting an ideal cut. Sparkle is obviously number one. I'm getting the classic six prong setting from blue nile. What do you guys think I should do? My ring size is about 3 1/2 or 4 so I have tiny fingers. Pictures of your own are definitely welcome.

 

[Lorelei]

I'm finally getting an engagement ring soon (we've been 'engaged' for a while, but had just bought a house that needed fixing up so it hasn't been in the cards til now). Since I've had so much time to think about it, I'm really having some trouble deciding on my diamond. The biggest I'm going to be able to go is about .7 carats (about 5.7 mm). If I go with that I'm looking to get at least a G in color, but preferably F and an eye clean SI1 or SI2. If I go a little smaller, like .63 (5.4/5.5 ish mm), I'll be able to get an F or E and VS2 in clarity. OR I could go a little bigger than the .7 but probably have to go down to I in color and stick with an eye clean SI2. No matter what, I'm getting an ideal cut. Sparkle is obviously number one. I'm getting the classic six prong setting from blue nile. What do you guys think I should do? My ring size is about 3 1/2 or 4 so I have tiny fingers. Pictures of your own are definitely welcome.

Hi Lynzee and welcome!

Your requirements sound fine, I would just mention don't take the term ' Ideal Cut' as a guarantee of getting a well cut diamond, some vendors use the term rather leniently to describe some of their stones, so do make sure to consider all the proportions of any diamonds you are interested in and don't go by terms such as the above or even some lab cut grades. Diamonds that have the AGS0 cut grade however are normally fairly safe bets to be well cut and excellent performers. To make it easier if you wish, post the proportions and any info you have of the diamonds you are interested in here and we can help you evaluate them.

Also SI clarity grades can be a definite option, but do make sure someone trustworthy can inspect the diamond for you and tell you whether the diamond is eyeclean to YOUR particular standards or not. This is a very useful thread by our Coatimundi which goes into further detail.

https://www.pricescope.com/journal/what_eye_clean_diamond/

If you have a look through our Show me the Bling forum, there is a thread there which shows diamonds of under 1 carat, often posters add their finger sizes also to give a visual idea of how the carat sizes look. You might find also that some posters might add photos of their rings to this thread for you.

I hope this helps and if and when you have questions, don't hesitate to ask.

 

[LynzeeLeigh]

Thank you! All of the diamonds I'm looking at have been graded by GIA and have a cut grade of "excellent." Do you know of a link that would give the table and depth percentiles I should stay within?

 

[z]

you can use the HCA tool to help you eliminate choices (everyone says it's a tool to eliminate choices, not for selection).

https://www.pricescope.com/tools/hca

open the GIA certs and plug the numbers into the tool and it gives some great info on how the stone will perform.

 

[Lorelei]

Thank you! All of the diamonds I'm looking at have been graded by GIA and have a cut grade of "excellent." Do you know of a link that would give the table and depth percentiles I should stay within?

You are welcome Lynzee! Z helpfully linked the Holloway Cut Advisor which is a very useful tool, I would just add that the HCA really cannot say how a diamond will perform, it cannot physically see the diamond and it is only offering basic estimations on performance. What it does is to help you eliminate diamonds which possibly won't be the best performers, the aim is to score 2 or below then you evaluate from there with images such as Idealscope.

As for proportions, you can use the HCA as a first round elimination, stones which score 2 or below are then deemed worthy of further evaluation.

Otherwise you can use the proportions listed below but bear in mind there are other proportion configurations out there which can produce beautiful stones, the following is a guide and is intended to be used as such.


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!

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 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)."