GIA EX symmetry/ 8 symmetrical arrow=hearts & arrows?

[chictomato]

Hi there does, GIA excellent symmetry equates to hearts and arrow? I have a mounted stone, I am able to see 8 symmetrical arrows with a Ideal scope, does its means its a hearts and arrow diamond? However, I am not sure how it looks from bottom up as its mounted. Tks!

 

[stone-cold11]

There is no way to see the Hearts image once the stone is mounted.

Seeing the arrows image does not imply a perfect hearts image. And GIA does not grade it's symm grade based on optical symm which is what a H&A image grades.

 

[Lorelei]

Date: 9/9/2009 8:00:26 AM
Author:chictomato
Hi there does, GIA excellent symmetry equates to hearts and arrow? I have a mounted stone, I am able to see 8 symmetrical arrows with a Ideal scope, does its means its a hearts and arrow diamond? However, I am not sure how it looks from bottom up as its mounted. Tks!

Once a diamond is mounted you can no longer see hearts in their entirety from the bottom of the diamond. Also just because a diamond shows an arrow pattern doesn't necessarily mean it is a ' true' h&a.

Concerning the above these are different types of symmetry, GIA symmetry is " physical" symmetry concerning how well all the facets, table, culet, outline of the diamond line up etc, optical symmetry is responsible for the hearts and arrows seen in some diamonds, this is different to physical symmetry. Top optical symmetry shows the overall cut precision and how well the virtual faceting works to result in h&a patterning etc. Because a diamond has Excellent GIA symmetry does not mean it has great optical symmetry and will therefore show precise h&a patterning.

Read more here on physical symmetry

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

Hope this helps!

 

[WinkHPD]

Date: 9/9/2009 8:00:26 AM
Author:chictomato
Hi there does, GIA excellent symmetry equates to hearts and arrow? I have a mounted stone, I am able to see 8 symmetrical arrows with a Ideal scope, does its means its a hearts and arrow diamond? However, I am not sure how it looks from bottom up as its mounted. Tks!

Absolutely not. It is both possible and common to have GIA excellent and AGS Ideal cut grading on diamonds that do not display Hearts and Arrows.

Since your diamond shows a good Arrows pattern there is a fairly good chance that it will also display passible to excellent hearts, but we have no way to know that without removing the diamond for observation.

Conversely, it is possible to have good to excellent Hearts and Arrows on a diamond that does not meet the parameters of GIA/AGS Ex/Ideal parameters. A stone with perfect optical symmetry might have some physical symmetry problems that can remove it from the GIA/AGS top cutting grades.

If you are happy with the diamond then this is probably an issue that you need not worry about. It would be a shame to possibly damage either the mounting or the diamond trying to take it out to satisfy your curiosity. If you are not happy with the diamond then this becomes more of an issue. I will admit to seeing only a few GIA Ex that I did not personally like, and I have not yet seen an AGS Ideal that I did not like personally. There may be some out there, I just have not yet seen one.

Wink

 

[Todd Gray]

Date: 9/9/2009 8:00:26 AM
Author:chictomato
Hi there does, GIA excellent symmetry equates to hearts and arrow? I have a mounted stone, I am able to see 8 symmetrical arrows with a Ideal scope, does its means its a hearts and arrow diamond? However, I am not sure how it looks from bottom up as its mounted. Tks!

Definitely NOT. The arrows pattern within a diamond is a distorted reflection of the eight pavilion main facets located on the underside of the diamond and the hearts are a reflection of the kite shaped bezel facets located on the top half of the diamond... Just because one section of the diamond is cut to exhibit nice arrows does not mean that the other half of the diamond has been properly faceted and with the right angles to exhibit a crisp and complete pattern of hearts. It is much more difficult to cut a diamond to exhibit crisp and complete hearts than arrows... The only way to determine whether a diamond exhibits a crisp and complete pattern of hearts and arrows is to view the diamond while unmounted through a Gems Fantasy Scope or other imaging system.

 

[chictomato]

Thanks to all the input!