Is this a good diamond?

[momx2]

We are going to look at rings next week, and of course my boyfriend has not done the research that I told him that he needed to do before we go to the diamond district in NYC. So now I am left to do the job at the last minute. I came across these diamonds on Blue Nile and I am a little interested. Do you think it is a good buy? Clarity (VS2/VS1) and color (G minimum) is more important to me than size so I would go down to a .9ct if it meant that I was getting a better diamond especially since it will be set in a pave setting which makes the diamond look bigger anyway. I would like to keep the price of the diamond to around $5k. Thank you in advance!

http://www.bluenile.com/round-diamond-1-carat-very-good-cut-g-color-vs2-clarity_LD01339363#

http://www.bluenile.com/round-diamond-1-carat-or-less-very-good-cut-g-color-vs2-clarity_LD01140147

http://www.bluenile.com/round-diamond-1-carat-ideal-cut-g-color-vs2-clarity_LD01400422

 

[Lorelei]

Hi momx2

Yay! I could actually view these BN links for once ( I often have trouble for some reason). Anyway out of your selections the only one worth consideration is the last due to the cut proportions/ cut quality and I would really want an Idealscope image for it but BN don't offer these. Would you like us to hunt up some suitable diamonds from BN if you prefer to buy from there?

Cut quality is critical if you are to end up with a pretty stone, so very important to concentrate on that.

The NY diamond district can be a minefield for the rookie, so I would suggest if you want to go there, make appointments with these vendors.

www.exceldiamonds.com

www.jamesallen.com ( have offices there although based in MD)

www.engagementringsdirect.com

Also if you are open to a trip to Long Island, www.goodoldgold.com see clients by appointment.

 

[stone-cold11]

Another in the diamond district NYC is IdJewelry, http://www.idjewelryonline.com/

 

[momx2]

I don''t necessarily perfer to purchase online, but I want to keep my options open...you never know they could have something good out there. I would really appreciate it if you could come up with something.

Thanks for the recommendations I will make my appointments this morning. My fear is that we will be taken in so I am going to marry this forum over the next couple of days to have some idea of what I am looking at.

What do you mean by cut proportions? Is the fact that it is graded by GIA as a certain cut grade sufficient enough? What should I be looking for when trying to pick out a quality diamond in regards to cut proportions...is there some type of range? Being that I am looking for the best quality within my budget would it be best that cut proportions dictate my decision as a general rule?

Thanks for all your help!

 

[stone-cold11]

GIA cut grading allows for proportion that are less than ideal, allowing for leakage. So do not trust it entirely, use the idealscope or ASET scope, if they are available from the vendors, to check if there is leakage.

More info on Idealscope/ASET.

http://www.highperformancediamonds.com/index.php?page=education-performance

By cut proportion we meant the all the numbers presented in the profile schematic of the diamond on the grading report, the table, depth, crown (CA) and pavilion angles (PA), girdle variation, star and lower half numbers.

Generally, table 54-60%, depth <62.7%, CA 33.5-35.0, PA 40.6-41.0, girdle variation thin - slightly thick.

CA and PA has an inverse relationship, if you have a CA of 33.5 a PA of 41 will complement it, at CA of 35, a PA of 40.6-40.8 will be better.

Use this tool as a rejection tool, https://www.pricescope.com/cutadviser.asp, basically it will take care of the angles and table relationship of the above paragraph. A score below a 2 is worthy of further examination if you are buying online blind. If more information is available, such as ASET/IS image, score up to 3 can still be a good performer.

 

[Lorelei]

Date: 10/9/2009 6:44:50 AM
Author: momx2
I don't necessarily perfer to purchase online, but I want to keep my options open...you never know they could have something good out there. I would really appreciate it if you could come up with something.

Thanks for the recommendations I will make my appointments this morning. My fear is that we will be taken in so I am going to marry this forum over the next couple of days to have some idea of what I am looking at.

What do you mean by cut proportions? Is the fact that it is graded by GIA as a certain cut grade sufficient enough? What should I be looking for when trying to pick out a quality diamond in regards to cut proportions...is there some type of range? Being that I am looking for the best quality within my budget would it be best that cut proportions dictate my decision as a general rule?

Thanks for all your help!

Cut proportions refers literally to the proportions of a diamond, depth, table, crown and pavilion angles etc. Here are some numbers we use as a guide to help others find a well cut round diamond.

depth - 60 - 62% - although my personal preference is to allow up to 62.4% ( try to avoid going deeper than this as you can start to lose face up size or spread)
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!

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

From expert John Pollard.

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).