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color
clarity

Experts in reading ASET images and IDEAL scopes,help to see if the stone has obstruction !

Karl_K

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There is nothing wrong with you, you just haven't reached mind clean with it.
 

Golden_bird

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I agree they have logic behind categorizing stones as "excellent". The problem is the criteria to hit the "excellent" category is very broad so you end up with many stones that aren't that excellent at all.

While no stone will ever be perfect, you can find stones with the right proportions, good images, etc. Small imperfections may not be noticeable to the naked eye, but just arbitrarily trusting the term "excellent" can set yourself up for failure IMO.




Correct. No stone is perfect, not even super ideals. Heck, I can use the BGD stone I got my fiancee as an example. While it squeaks by on some of the proportions it simply is NOT the stone I would pick out today after having learned so much. The table is too big and the crown is too shallow. Consequently it produces more white light return and has bigger spread for it's weight. Technically this doesn't make it any less ideal, but rather just a personality type I wouldn't pick within that ideal range.

I was seriously contemplating an upgrade for her a few months back but then got hit with some unexpected funeral expenses. Between that and wedding expenses and also the fact we are going to foster/adopt a kid in need we just felt it was best to wait on the stone upgrade. Plus the fiancee is self employed and still building her business so I'm carrying the majority of the financial load.

Not that you need my life story, but my point was you have to be happy with whatever you own. I don't think the imperfections in your stone make it any less beautiful. I haven't seen it in person but the pictures look amazing and would be hard pressed to spend more money on something that you can't notice (as you said you had some ACA's to compare against).
You are very right Sledge ! Today ppl find wonky cut old European stones even more beautiful than mastered to perfection modern stones. I just got stuck in over analyzing . It’s always something better -bigger -white -sparkler ! It’s much more amazing that you have decided to foster /adopt a child !!! They are the biggest diamonds in your life !the good thing about them is with time ,real diamonds”shrink” ,children only grow bigger nd shine brighter .and you never tired of them :))they always bring you joy ! I have to stop this drama over nothing.....I love the taller crown of my stone ,looks like a delicious cupcake :)) what’s are the stats of your diamond ?? You have your whole life to upgrade or just buy something deferent and repurpose the diamond ,like the necklaces -closer to heart ❤️
 

Karl_K

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Golden_bird

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Please forget the nuisances, this is a beautiful stone! If you really want peace of mind about the aset, just buy one for 30 dollars or whatever it is and take a new aset. It won't change the fact this is a great performer with lovely proportions, but you might find peace having a picture perfect ASET, the other one is simply over obstructed.
I have constructed one myself :)))hahaha I was trying to order one form ags ,but they never responded to me so I gave up on that idea . In my handmade I don’t see this overblue ! But also I don’t know if I use it right :))
 

Golden_bird

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lots of viewing in all kinds of lighting.
That is what your buying is how it looks to you.
To my eyes, it looks perfect in all lighting ! Very clear crystal ,no inclusion from any point , no fluorescence, i even broght it to mall today :))) bcs they have the best lighting in some stores /)) that’s my brain which stuck with numbers !
 

Serg

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Even absolutely correct ASET image gives misleading information about real head obscuration even for round diamonds.

There are positive and negative Head obscuration . Negative is when both eyes see obscuration in same time in same diamond facet . Positive head obscuration when only one eye sees obscuration in same time in same diamond facet.
ASET does show any difference between these two types head obscuration.
ASET light has Cyclops head obscuration 30degree( -/+15 degree)
A human eye obscuration in horizontal plane is in 2.5 times less in one direction then in opposite direction.

This phenomena is very important for Brilliancy phenomena creation.
Screenshot 2018-12-15 10.24.13.png Screenshot 2018-12-15 10.25.53.png
 

Golden_bird

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Even absolutely correct ASET image gives misleading information about real head obscuration even for round diamonds.

There are positive and negative Head obscuration . Negative is when both eyes see obscuration in same time in same diamond facet . Positive head obscuration when only one eye sees obscuration in same time in same diamond facet.
ASET does show any difference between these two types head obscuration.
ASET light has Cyclops head obscuration 30degree( -/+15 degree)
A human eye obscuration in horizontal plane is in 2.5 times less in one direction then in opposite direction.

This phenomena is very important for Brilliancy phenomena creation.
Screenshot 2018-12-15 10.24.13.png Screenshot 2018-12-15 10.25.53.png
Ok now I am completely complicated :lol-2: esp when you add “cyclop “ eye . It’s all technical details which make my head spin around . I am simple girl who just wants a sparkly diamond . Please , tell me your opinion :))
 

Golden_bird

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There is nothing wrong with you, you just haven't reached mind clean with it.
Karl ! I am bothering you again !but I finally figure out what bugs me ! It’s HCA score of 0.8 !Also it’s usually recommend to get a diamond between 1-2 for a ring .Or it’s a more of concern of shallow combos like 34/40.6 ? Thank you again ! I am almost there :mrgreen2::mrgreen2::mrgreen2:
 

Karl_K

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Karl ! I am bothering you again !but I finally figure out what bugs me ! It’s HCA score of 0.8 !Also it’s usually recommend to get a diamond between 1-2 for a ring .Or it’s a more of concern of shallow combos like 34/40.6 ? Thank you again ! I am almost there :mrgreen2::mrgreen2::mrgreen2:
This one isn't one of the ones with issues, some of them that score under 1 are better in earrings and pendants.
If this one had an issue you would have seen it.
You know more about it than 99.99%+ of the trade.
 

Karl_K

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Ok now I am completely complicated :lol-2: esp when you add “cyclop “ eye . It’s all technical details which make my head spin around . I am simple girl who just wants a sparkly diamond . Please , tell me your opinion :))
Close one eye and the all diamonds looks totally different is the basis of the cyclop comment.
Humans do have a dominant eye to varying degrees that makes it complicated as some people are actually more like cyclops than others.
Further people rarely put the diamond exactly between both eyes when viewing it.
They tend to hold the diamond more towards the dominate eye side.
That the ring is on one hand also raises the trend to look at it not centered between the eyes.
That is the basis of his second image, combined with both eyes seeing different degrees of obstruction.
It is one of the reasons the ASET obstruction model is badly broken.
But all that matters not a bit when your looking for the issue with your own eyes how you look at it.

Edit: the above is not 100% correct but close enough for now, its is even more complex.
 
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Golden_bird

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This one isn't one of the ones with issues, some of them that score under 1 are better in earrings and pendants.
If this one had an issue you would have seen it.
You know more about it than 99.99%+ of the trade.
Thank you Karl ! I think I finally found a peace (mind clean )and missing puzzle. Now I can relax and don’t scrunch it under all normal and obnormal ways to find a fault :)) now I will put my energy into creating a setting and let it shine :)):appl:
 

Serg

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Karl ! I am bothering you again !but I finally figure out what bugs me ! It’s HCA score of 0.8 !Also it’s usually recommend to get a diamond between 1-2 for a ring .Or it’s a more of concern of shallow combos like 34/40.6 ? Thank you again ! I am almost there :mrgreen2::mrgreen2::mrgreen2:

My Advice to any consumer: Do not use ASET as final instrument to grade a cut optical performance ( specially for fancy cuts). You need high experience to avoid any misunderstanding in ASET image interpretation even for RBC. The best way to select your diamond is direct comparison with best references that you can find. It is wise during direct comparison to use RBC AGS0 or GIA 3EX with P41CR34.5T57 LGF80% , Color G or better, Clarity VS2 or better, similar size as your diamond.( all diamonds have to be cleaned well before comparison)
Sometimes it is difficult and it is reason why H&A, IS, ASET become so popular for RCB selection.
But it is same way if you buy car without test drives. Will you buy car without test drive?
 

gm89uk

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Just interested @Serg, why 34.5/41/57 with 80% LGF as a reference?

Do you mean specifically with this particular diamond as it will be a different flavour?
 

crbl999

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Just interested @Serg, why 34.5/41/57 with 80% LGF as a reference?

Do you mean specifically with this particular diamond as it will be a different flavour?

Curious about this as well. This combo is on the edge of AGS Ideal. I would prefer 34.5/40.7 with a 57 table.
 

sledge

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The best way to select your diamond is direct comparison with best references that you can find. It is wise during direct comparison to use RBC AGS0 or GIA 3EX with P41CR34.5T57 LGF80% , Color G or better, Clarity VS2 or better, similar size as your diamond.( all diamonds have to be cleaned well before comparison)

Just interested @Serg, why 34.5/41/57 with 80% LGF as a reference?

Do you mean specifically with this particular diamond as it will be a different flavour?

Curious about this as well. This combo is on the edge of AGS Ideal. I would prefer 34.5/40.7 with a 57 table.

@Serg, I'm also curious the reasoning these particular specs. Would greatly appreciate a follow up response.

Also, do you have any more documentation (web links, etc) you could share on the "cyclops" effect discussed a few threads earlier?
 

Serg

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1) I doubt that many consumers and professionals could see difference between 34.5/41/57 and 34.5/40/57 during blind tests
2) For my taste I prefer diamonds with more Fire . again for my taste 34.5/41.2/57 has better Fire-Brilliancy balance than 34.5/40.7/57 .
34.5/41/57 is good compromise .

re:Also, do you have any more documentation (web links, etc) you could share on the "cyclops" effect discussed a few threads earlier?

http://www.gem.org.au/ckfinder/userfiles/files/GAA_Journal_V25_No3_web2(1).pdf
Pages 96-99
 

Karl_K

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Serg said the key word taste.
Others use the word balance.
My pick for a reference would be slightly different than his.
super tight 55t/34c/41p/70-80%/60% stars.
or a well cut 56t/35c/40.6p/77lgf%
That is 2 references with slightly different personalities across different lighting conditions.
Yet both would be references for comparison for me and I would not be picky about a table 1% either side or other minor differentiates in the combo(lgf%) on the theme.
Getting a group of cut nuts to agree to any one reference would not be likely to happen.
 

Golden_bird

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Serg said the key word taste.
Others use the word balance.
My pick for a reference would be slightly different than his.
super tight 55t/34c/41p/70-80%/60% stars.
or a well cut 56t/35c/40.6p/77lgf%
That is 2 references with slightly different personalities across different lighting conditions.
Yet both would be references for comparison for me and I would not be picky about a table 1% either side or other minor differentiates in the combo(lgf%) on the theme.
Getting a group of cut nuts to agree to any one reference would not be likely to happen.
Yeah you need to see lots of diamonds to pick the flavor you like ! I fall in love with higher crown diamonds ! I have a 60/60 diamond -aka ppl call it flat top :lol: -it’s lovely and I have been always happy with it before I found out prisecope and how many negatives comments these diamonds are usually recive . Did I get under influence ? Maybe or maybe be not . I just decided to try something else . Why not ? I also have ACA diamond as a model :)) EFCCC248-4AEA-42B8-A0FD-AF4AC5C2A64C.jpeg that’s the one I am comparing my new diamond to !! And I notice that new stone gives more colored flashes and I like it ! I am also soo happy that you @Karl_K like this not super popular 35/40.6 combo :)) and 40.6 angle is not that dangerous as HCA says.That what was giving me confusion and doubted my choice.
 

Karl_K

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Serg said the key word taste.
Others use the word balance.
My pick for a reference would be slightly different than his.
super tight 55t/34c/41p/78-80%/60% stars.
or a well cut 56t/35c/40.6p/77lgf%
That is 2 references with slightly different personalities across different lighting conditions.
Yet both would be references for comparison for me and I would not be picky about a table 1% either side or other minor differentiates in the combo(lgf%) on the theme.
Getting a group of cut nuts to agree to any one reference would not be likely to happen.
Fixing typo in numbers.
 

gm89uk

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So @Karl_K in a perfect world you think 56t for 35/40.6 rather than 54-55?
 

Karl_K

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So @Karl_K in a perfect world you think 56t for 35/40.6 rather than 54-55?
Anything from 54-57 maybe 58 would work. I would like a 50t to but lets keep it mainstream.
I picked 56 because it is a near universal table size like 55 and I had already said 55 :}
With a 35.5 crown i would lean more towards 53-55.
54 vs 58 would make for a visible difference in personality all things equal.
Remember when you change one thing it does not just change one thing it changes a lot of relationships and other angles and heights.

Near universal means works with the widest range of other possible combinations.
 
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Golden_bird

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Anything from 54-57 maybe 58 would work. I would like a 50t to but lets keep it mainstream.
I picked 56 because it is a near universal table size like 55 and I had already said 55 :}
With a 35.5 crown i would lean more towards 53-55.
54 vs 58 would make for a visible difference in personality all things equal.
Remember when you change one thing it does not just change one thing it changes a lot of relationships and other angles and heights.

Near universal means works with the widest range of other possible combinations.
Thank you Karl for reassurance again ! I am so thankful for your help to figure out all these numbers ,images and possibilities . You def need much more to understand diamonds :))))
 

Golden_bird

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My Advice to any consumer: Do not use ASET as final instrument to grade a cut optical performance ( specially for fancy cuts). You need high experience to avoid any misunderstanding in ASET image interpretation even for RBC. The best way to select your diamond is direct comparison with best references that you can find. It is wise during direct comparison to use RBC AGS0 or GIA 3EX with P41CR34.5T57 LGF80% , Color G or better, Clarity VS2 or better, similar size as your diamond.( all diamonds have to be cleaned well before comparison)
Sometimes it is difficult and it is reason why H&A, IS, ASET become so popular for RCB selection.
But it is same way if you buy car without test drives. Will you buy car without test drive?
Thabk you Serg!!:) я подозреваю что вы тот русский гемолог ,про которого все тут говорят :)) Я из Беларуси :) приятно ,что наши люди тут тоже есть ❤️ Вы навкрное находитесь в России ,так ?:)
 

sledge

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1) I doubt that many consumers and professionals could see difference between 34.5/41/57 and 34.5/40/57 during blind tests
2) For my taste I prefer diamonds with more Fire . again for my taste 34.5/41.2/57 has better Fire-Brilliancy balance than 34.5/40.7/57 .
34.5/41/57 is good compromise .

re:Also, do you have any more documentation (web links, etc) you could share on the "cyclops" effect discussed a few threads earlier?

http://www.gem.org.au/ckfinder/userfiles/files/GAA_Journal_V25_No3_web2(1).pdf
Pages 96-99

Thank you for sharing the logic on your preferred diamond proportions. We all have slightly different tastes but I understand how that factors into the equation. Since originally buying my own tastes have changed and I would have bought my fiancee a different stone if I could get a re-do.

Also, thank you for sharing that link. I will do some reading. ;)2


I am also soo happy that you @Karl_K like this not super popular 35/40.6 combo :)) and 40.6 angle is not that dangerous as HCA says.That what was giving me confusion and doubted my choice.

I hope you understand the 40.6 pavilion isn't bad by itself. The other proportions come into play as well, most notably the crown angle. Putting a 34/40.6 together wouldn't have the same result as your 35/40.6. This is what @Karl_K means when he says everything has relationship to one another. You can change one variable and it affects quite a bit. This is why I have started including a "angles must be complimentary" statement when I list ideal proportions to search.

The 35/40.6 is quite lovely and fairly popular. It pairs a steep crown with a shallow pavilion which is complimentary. That key word again, complimentary. It was some of other images that gave concern, but those have been been talked over and concluded they were bad angles, etc that gave a worse appearance than the actual stone represents.

Since I did not write the HCA I am not familiar with the logic, but I do know you have to enter crown angle, pavilion angle, table % and depth %. In short, it's taking all 4 of these values and making calculations and assumptions about what the stone could potentially represent.

At the end of the day, the HCA tool is useful but it's nothing more than an elimination tool. Meaning if it's less than 2 then the stone is worth a closer look. If it's greater than 2, you should probably keep looking. Yes, it also says most stones between 1-2 are preferable for e-rings...the key word here is most. However, the HCA tool lacks additional sophistication to be more than a check before proceeding onto review of advanced images & in-person examination.

You did things right when selecting this stone:
  1. You narrowed the field to those stones with ideal proportions.
  2. You then found a stone that had complimentary proportions.
  3. You ran the HCA tool for elimination.
  4. You requested and analyzed the images.
  5. You decided to purchase and examine the stone in person.
  6. You have determined the stone is as beautiful as your ACA.


Thabk you Serg!!:) я подозреваю что вы тот русский гемолог ,про которого все тут говорят :)) Я из Беларуси :) приятно ,что наши люди тут тоже есть ❤️ Вы навкрное находитесь в России ,так ?:)

I cannot answer for Serge, but his company OctoNus is located in Moscow so I assume he is also located in Russia. ;)2
 
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Karl_K

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and 40.6 angle is not that dangerous
A true 40.6 pavilion works well with the widest range of proportions than any other pavilion angles.
It is the near universal pavilion angle.
But it is close to edge and gia rounding can hide one over the edge.
Not an issue in your case.
 
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Golden_bird

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Thank you for sharing the logic on your preferred diamond proportions. We all have slightly different tastes but I understand how that factors into the equation. Since originally buying my own tastes have changed and I would have bought my fiancee a different stone if I could get a re-do.

Also, thank you for sharing that link. I will do some reading. ;)2




I hope you understand the 40.6 pavilion isn't bad by itself. The other proportions come into play as well, most notably the crown angle. Putting a 34/40.6 together wouldn't have the same result as your 35/40.6. This is what @Karl_K means when he says everything has relationship to one another. You can change one variable and it affects quite a bit. This is why I have started including a "angles must be complimentary" statement when I list ideal proportions to search.

The 35/40.6 is quite lovely and fairly popular. It pairs a steep crown with a shallow pavilion which is complimentary. That key word again, complimentary. It was some of other images that gave concern, but those have been been talked over and concluded they were bad angles, etc that gave a worse appearance than the actual stone represents.

Since I did not write the HCA I am not familiar with the logic, but I do know you have to enter crown angle, pavilion angle, table % and depth %. In short, it's taking all 4 of these values and making calculations and assumptions about what the stone could potentially represent.

At the end of the day, the HCA tool is useful but it's nothing more than an elimination tool. Meaning if it's less than 2 then the stone is worth a closer look. If it's greater than 2, you should probably keep looking. Yes, it also says most stones between 1-2 are preferable for e-rings...the key word here is most. However, the HCA tool lacks additional sophistication to be more than a check before proceeding onto review of advanced images & in-person examination.

You did things right when selecting this stone:
  1. You narrowed the field to those stones with ideal proportions.
  2. You then found a stone that had complimentary proportions.
  3. You ran the HCA tool for elimination.
  4. You requested and analyzed the images.
  5. You decided to purchase and examine the stone in person.
  6. You have determined the stone is as beautiful as your ACA.




I cannot answer for Serge, but his company OctoNus is located in Moscow so I assume he is also located in Russia. ;)2
.
Thank you @sledge ! You are awesome ! I think you found such a passion in diamonds and I am more than sure that your life and profession somehow connected with physics/math. You glow from the screen when talk about numbers:)) ;)2 I finally reach “ mind clean “ state of mind and now can connect to the stone and start enjoying it . I took it to different location : outside, to the store ,sunny weather -rainy weather . It behaves great everywhere ! Color wise , I cannot tell them apart :my GIA H and I . Maybe they right when talking about that AGS little bit soft on color (saw ags J and it was too yellow from the side ,like dark )
 

Golden_bird

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A true 40.6 pavilion works well with the widest range of proportions than any other pavilion angles.
It is the near universal pavilion angle.
But it is close to edge and gia rounding can hide one over the edge.
Not an issue in your case.
Karl! Thank you for taking your time and share such valuable information - your knowledge -with all of us for free:)))) so hard to find nowadays . Thank you for putting all together and helping me to pick the diamond in my budget and not overspend on things I will not be able to tell apart and appreciate. Thank you For making little online Christmas miracle :))) I will definitely share the final “product “:)))
 

Karl_K

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Your welcome, looking forward to more pictures!!!!!! If you remember @Karl_K when you post the ring because I dont get around to show me the ring that often.
 

TreeScientist

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Another thing worth mentioning, seeing as it hasn't been covered yet. As @Karl_K mentioned, a true 40.6 pavilion angle works with just about everything between 34-35.5 CA and won't cause any obstruction issues. The problem is when one (or multiple) of the pavilion mains drops below about 40.45. This will result in obstruction issues.

A quick "hack" to get a better idea of where a GIA-rounded 40.6 pavilion angle actually lies is to look at the pavilion depth. A true 40.6 pavilion angle, in the complete absence of a culet (more on that in a minute), will result in a pavilion depth of 42.8%, which will be rounded to 43%. Thus, if the pavilion depth of a GIA diamond is 43%, then the diamond is almost guaranteed (like 99% certainty) to have an average pavilion angle of 40.6 or above. On the other hand, if the pavilion depth is listed as 42.5%, then there's a high likelyhood that the mean pavilion angle lies somewhere between 40.5-40.6. Now, this is not always the case, because even if the culet is listed a 0%, there still may be a culet up to about 0.1%, so that could throw off the measurements. But if the pavilion depth is listed as 42.5%, THIS is when you need to start being cautious of obstruction issues.

Your diamond has a 43.0% pavilion depth, meaning the average pavilion angle is almost certainly between 40.6-40.7, and the pavilion mains are likely fairly uniform judging by the symmetry of the arrows in the IS image. So it is highly, highly unlikely that any of the individual pavilion mains would drop below 40.5, let alone 40.45.

TL;DR version: You having nothing to worry about in the obstruction department. The ASET was just poorly aligned, which resulted in those blue areas. Your diamond is beautiful. :)

Just in case you needed even more "mind clean" reassurance. ;-)
 
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