Idealoscope and ASET scope - opinion

[Lady_diamond]

I finally managed to get an idealoscope and ASET scope.
It was difficult taking photos of a mounted diamond.
What do you think of the images?
I think I can see light leakage on one side of the diamond between two arrow heads.
Do you think this diamond is a keeper?
Macroscopically its sparkly and firey.

Specifications:
F VVS2 1.58ct
Crown angle 34
Pavillion angle 40.8
Table 56%
Medium facet 3.5%
50% ?star facet
80% lower girdle facet length
Cutlet - none
15% crown depth
Total depth 61.6%

your views will be appreciated!

 

[John P]

Given that it's mounted, you managed to capture some excellent shots.

Based on the average angles it seems like correct orientation of the girdle plan with the ASET cone in shot #2, which is important to interpretation.

I think I can see light leakage on one side of the diamond between two arrow heads.

Okay, let's be picky. If the scopes are level (they seem to be) there is slight deviation from normal indexing at the 3:30 position, seen as a bit of green in the upper-girdle facets in ASET, with an accompanying non-red area between the mains; which is gray in ideal-scope. No way to judge the severity, since the ring's shank runs parallel underneath and blocks the backlighting. There's also some indexing deviation at 6:30, but only affecting the upper-girdle facets, and a prong covers most of that.

Now let's be practical. Only the pickiest gemologists would analyze the diamond to this degree. And, while not as finely-tuned as the very top precision cuts, what's seen above would not knock it out of GIA EX, or AGS 0 light performance. The light return level is what I'd expect from the average measurements and angles you cited, which indicated robust performance on paper; confirmed by the scopes. Nice work.

 

[Karl_K]

They are pretty good, good job.
They are good enough to be useful if you want picky....
The IS image the stone is just a bit to far into the scope and a little brighter back light would help.
ASET could use a little more light also.

Sir John I am seeing a bunch of diamonds with similar ASET signatures on several sites.
Almost perfect except for one area of painting or digging.
Any idea why they are so common these days?

 

[John P]

Sir John I am seeing a bunch of diamonds with similar ASET signatures on several sites.
Almost perfect except for one area of painting or digging.
Any idea why they are so common these days?

They've always been around. I see plenty in showrooms calling in other suppliers' XXX or Ideal stones when I use ASET on them.

I would attribute it to expanded use of ideal-scope and ASET images. I'm sure you remember when the diamonds offered by the (few) reflector-using PS sellers all seemed to have perfect or near-perfect LR footprints? As more companies get involved the reflector-images are extending to diamonds without such perfect cutting.

That's refreshing to me, as it promotes context: We still rarely see anything here that's not above-average in RBs. I'm sure you know what I mean, as you've used the scopes in plenty of commercial stores too...

 

[Karl_K]

Thanks Sir John that makes sense.

 

[Lady_diamond]

Given that it's mounted, you managed to capture some excellent shots.

Based on the average angles it seems like correct orientation of the girdle plan with the ASET cone in shot #2, which is important to interpretation.

I think I can see light leakage on one side of the diamond between two arrow heads.

Okay, let's be picky. If the scopes are level (they seem to be) there is slight deviation from normal indexing at the 3:30 position, seen as a bit of green in the upper-girdle facets in ASET, with an accompanying non-red area between the mains; which is gray in ideal-scope. No way to judge the severity, since the ring's shank runs parallel underneath and blocks the backlighting. There's also some indexing deviation at 6:30, but only affecting the upper-girdle facets, and a prong covers most of that.

Now let's be practical. Only the pickiest gemologists would analyze the diamond to this degree. And, while not as finely-tuned as the very top precision cuts, what's seen above would not knock it out of GIA EX, or AGS 0 light performance. The light return level is what I'd expect from the average measurements and angles you cited, which indicated robust performance on paper; confirmed by the scopes. Nice work.

Thanks John Pollard for your input! I took more photos (this time with better backlighting as per suggestion of Karl). Do you think the diamond is cut slightly steeper in the area that are non-red and gray? Looking at the diamond, I can't say the spread or that area visibly affected. I can post a photo of the diamond.

I paid $17.1K (before tax) for the diamond. Worth keeping for that price?

 

[Lady_diamond]

Thanks Karl for the suggestion, I took more images with better lighting (it was difficult!)

 

[Karl_K]

Thanks Karl for the suggestion, I took more images with better lighting (it was difficult!)

You did good.

17.1k is in the going rate.
If you use the search above you will find comps.

 

[John P]

Thanks John Pollard for your input! I took more photos (this time with better backlighting as per suggestion of Karl). Do you think the diamond is cut slightly steeper in the area that are non-red and gray? Looking at the diamond, I can't say the spread or that area visibly affected. I can post a photo of the diamond.

Just a deviation from normal indexing, likely affecting break facet pairs. Not necessarily steeper. It's a common occurrence in brillianteering, which is the final stage of polishing.

 

[Lady_diamond]

Thanks John and Karl for the information you are so knowledgeable! I feel safe now about keeping the diamond.

How does the final part of brillianteering - the polishing of the stone, can break the facet pairs? Can this be fixed?

Will you expect the area in which the facets are broken to be a bit more dull/dark compared to the rest of the diamond?

Also you said the numbers for the diamond is robust - can you tell by the numbers and the scope images whether this will be a diamond that is balanced in fire/brilliance, and does it tell you anything about brilliance contrast?

(Sorry for all the questions - I am intrigued and would like to learn!)

 

[John P]

You're quite welcome.

How does the final part of brillianteering - the polishing of the stone, can break the facet pairs? Can this be fixed?

The "break facets" are a trade-term for upper and lower girdle facets. Nothing was broken. The polisher just needed to shift some things during brillianteering.

Will you expect the area in which the facets are broken to be a bit more dull/dark compared to the rest of the diamond?

Not in casual viewing.

Also you said the numbers for the diamond is robust - can you tell by the numbers and the scope images whether this will be a diamond that is balanced in fire/brilliance, and does it tell you anything about brilliance contrast?

Great brightness and a nice even contrast pattern. The reflector images can't inform us about fire or scintillation but the numbers and images are in-line with a bright, firey, sparkly diamond. You're in a much better position than us to determine that. Take it out of those silly scopes, give it a nice cleaning and explore a bunch of different lighting scenarios. Most of all, enjoy!

 

[Lady_diamond]

The "break facets" are a trade-term for upper and lower girdle facets. Nothing was broken. The polisher just needed to shift some things during brillianteering.

I am guessing they started off from one end of the diamond and when they met up at the other end they realized it was uneven? Did they shift the girdle and the angle of the lower facet??

The reflector images can't inform us about fire or scintillation but the numbers and images are in-line with a bright, firey, sparkly diamond. You're in a much better position than us to determine that. Take it out of those silly scopes, give it a nice cleaning and explore a bunch of different lighting scenarios. Most of all, enjoy

Haha! I have
It looks very bright in normal lighting and even more bright and white under indoor lighting! Under spotlighting it sparkles crazily with beams of rainbows. Thank you for your HELP!!! I AM GRATEFUL FOR YOUR COMMENTS!!!

 

[Karl_K]

I agree with Sir John.. Enjoy!
Your welcome!