Diamond Measurements

[CausNeFTK]

Hi,

Was just after some opinions on the cut characteristics a diamond I have been looking at.

It is a 1.17ct F VS2

The proportions are:

Depth % - 61.9
Table % - 57
Crown Angle - 35.5 degrees
Pavilion Angle - 40.6 degrees
Crown Height % - 15.5
Star % - 50
Lower Half % 80

Just after general thoughts on light return etc

Cheers

 

[Dancing Fire]

No one will comment w/o a ASET or I-scope photo.

 

[CausNeFTK]

Oh Ok, I see if I can get one, Thanks

 

[Lorelei]

No one will comment w/o a ASET or I-scope photo.

Ok, I'll bite my American BF!

Hi Cause and welcome!

From the basic info, this diamond looks promising certainly but as DF says, an Idealscope or ASET image is needed now in order to see how well everything works together.

I take it the diamond is intended for an engagement ring? Is it for sale through a jewellery store or online vendor?

 

[CausNeFTK]

Hi and Thanks,

Yep it's for an engagement ring, from an online retailer.

 

[SirGuy]

Hi there! DF is quite right that we can't really make a determination about its light performance without images. The numbers look promising but on their own don't do too much. They're within a good range to where we'd request images like Ideal-Scope and ASET, because those numbers are promising enough for further investigation.

As far as the color and clarity, those are important to consider as well. Which lab did the report?

 

[CausNeFTK]

It is a GIA report

 

[SirGuy]

Cool! "F" is in the colorless range, and VS2 is a good one for clarity; its inclusions generally shouldn't be visible to the unaided eye.

Is your stone still unmounted? The best way to check out its light performance (except, of course, actually looking at it) is with an Ideal-Scope and ASET. These are reflector images that show how the different facets handle light return.

I quite enjoy this educational page on it:
http://www.highperformancediamonds.com/index.php?page=education-performance

 

[TC1987]

Crown Height % - 15.5
Star % - 50
Lower Half % 80

15.5% means it has adequate crown height. I always like to see at least 15% because I like mass above the girdle and also because flatter crown angles and lower crown height tends to produce less fire or the fire is out at the rim because the table is huge. (58% is not a huge table.)

80% lower half is a bit skinner arrow. I like mine at 76-77% for fat arrows.

Stars make the arrowheads, and don't have a good concept of what size translates to what look. But if they get the arrows wide enough (lower half) then the start facets / arrowheads have usually been correctly proportioned in the superideal H&A diamonds that I've looked at. This thread may or may not help explains what the star %s do (I didn't have time to follow all the links in it.)
[URL='https://www.pricescope.com/community/threads/what-does-star-length-and-lower-half-mean.46173/']https://www.pricescope.com/community/threads/what-does-star-length-and-lower-half-mean.46173/[/URL]

 

[Texas Leaguer]

It is a GIA report

Does the GIA report contain a cut grade? Even though the GIA cut grade system is quite broad, and you would still need more information to get a handle on light performance, it is useful to know.

 

[WinkHPD]

The thing that most concerns me about this diamond is the 40.6 pavilion angle. Because GIA uses such absurd rounding we can not know if this is a tightly cut 40.6 which should be good or if it is really got some problems with a Pavilion angle 40.4 on some of the facets and will thus have some obstruction issues.

I have to thus side with those who say that you need images. Even with the images, you will need to see it with YOUR eyes to know if YOU like it. This stone is on the borderline of being great, or being awful.

Wink

 

[CausNeFTK]

Thanks for all the info, really appreciate it. Lots more reading to do, I am also requesting an Ideal scope and will post that pic if I get one.

 

[CausNeFTK]

Hello again,

Couldn't get an Idea Scope or ASET for the previous diamond and while I was trying to organize payment the stone actually sold. But I think I may have found a diamond that has better proportions and is a grade in color and clarity up, only thing is it has medium blue fluro. I am asking for extra info on this new diamond too. This diamond is practically the same price as the first.

After some opinions on whether people think this is a good trade off.

Specs on new diamond.

1.2ct - E - VS1 - Medium blue Fluro - Ex/Ex/Ex

Girdle - Medium to Slightly Thick (4%)
Depth % 61.5
Table % 56
Crown Angle - 34
Pavilion Angle - 40.8
Crown Height % - 14.5
Star % - 50
Lower Half % - 80

Original Diamond Specs

1.17ct - F - VS2 - No Fluro - Ex/Ex/Ex

Girdle - Medium to Slightly Thick (4%)
Depth % - 61.9
Table % - 57
Crown Angle - 35.5 degrees
Pavilion Angle - 40.6 degrees
Crown Height % - 15.5
Star % - 50
Lower Half % 80

Cheers

Tony

 

[SirGuy]

Looks like it could be promising, Tony. Are you able to get images for this one?