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AGS "0" & Sarin Data Vs. HCA vs. Brilliance Scope

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Colored Gemstone Nut

Ideal_Rock
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Ok-Here' my inquiries to the cut geeks..lol


I am interested in the following stone:



Stone: Round Brilliant AGS "0" Hearts & Arrows Diamond
Weight:
.451 ct.
Depth Percentage: 60

Table Percentage: 57

Girdle Percentage: 1.0-1.4

Crown angle:34.8

Pavillion Angle:40.7

Dimensions:4.98-5.01*3

HCA Results in 4 excellents across the board based on posted sarin data. With an Overall score of (1) for total visual performance.

I like to use 3 things in evaluating a stone:

1.HCA - Based on Sarin Data or Mega Scope Readings (which measure the precision of cut.
2.B-Scope - Measuring the level of Brilliance, Fire, & Scintillation in a stone.
3. Like to take a peak at the Firescope to see How much leakage a stone has.

With all these things in mind consumers can get a great insight into how well a stone might perform. Of course the last determing factor is seeing the stone and being pleased with it.

My question is that I am aware that most sights have initial Sarin Data so plugging numbers into the HCA is easy. There are few sights that have B-scope Date and imaging to test leakage. (Good Old Gold & SuperBCert) For discriminating consumers like myself who like to have a good balance between the 3. What can a consumer expect from stones which might score high on the HCA in circumstances where B-scope readings and imaging to show leakage is not available.
I know there is a plethera of professionals on this sight so I want to hear you opinions. I am well aware that each stone has it's own characteristics & there is not a finite answer, but my main question is on the average how well to stones which rate high on the HCA rate on the B-scope. I know you guys have seen lots of stones come across yoour peering eyes so I want to hear everyones opinions.

Thanks in Advance-
Josh Rioux
Sitka, Alaska

 

Richard Sherwood

Ideal_Rock
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Josh, this should be an incredible stone. I've attached a DiamCalc simulated IdealScope image as another "check" in addition to the HCA scores, etc.

The Light Return Analysis comes out with "very goods" across the board, which is about the best you will see:

Light Return Mono.......Very Good 0.99
Light Return Stereo.....Very Good 0.98
(Non) Leakage Mono......Very Good 0.97
(Non) Leakage Stereo....Very Good 0.98
Contrast................Very Good 0.97
(Non) Fisheye Effect....Very Good 1.00

Wow.

-----------
IdealScope- In general, the darker pink areas indicate areas of greater light return, with the lighter pink areas indicating areas of lesser light return. The black areas indicate areas of greater contrast, with the gray areas indicating areas of lesser contrast. The white areas indicate areas of light leakage. A good explanation of the IdealScope image along with examples can be found at https://www.pricescope.com/idealscope_indx.asp

Disclaimer- The facet arrangement and symmetry of the image will probably vary from your actual diamond, which may affect the light performance indicated. The computer simulation is reproduced best when the actual diamond is being viewed and the image "tweaked" to the appearance of the diamond. However, this "blind" reproduction should be helpful on the major light performance aspects.
-----------

0.45.jpg
 

Colored Gemstone Nut

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Richard -Thanks for your response. Wow diamoncalc seems to be a great tool to evaluate a stone before actual tests are performed on the stone. The more information leads the consumer to make a more informed purchase. I really appreciate your time. I know the correlation between the HCA. Brilliance scope, and imaging equiptment have been answered somewhat on other threads, but it helps to take a little guessing out of the game by having some great people to give criticism based on technology they will share and I thank you for taking the time to do this for me. There have been many questions I have asked myself in buying a stone and one of them is I don't want to just rely on the HCA. Vendors on the internet are selling stones which usually have sarin data which you can plug into the HCA. My main question was what some of the vendors were seeing in direct correlation to HCA results vs. the brilliancescope results on a particular stone. I know that there are many different aspects involved in a diamond scoring very high in all 3 categories of the b-scope, but was also curious as to how stones without b-scope results would rate in direct correlation with what they scored on the HCA. Again I know there is not a finite answer, but was just curious as to any average trends vendors might see in comparison to the HCA and light return. I have read many different threads and have answered alot of my own questions without trying to post any redundant info. Just pure curiosity. I thank you again for your time Rich and welcome any other responses.

Josh Rioux
Sitka, Alaska


 

Richard Sherwood

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-----------
My main question was what some of the vendors were seeing in direct correlation to HCA results vs.
the brilliancescope results on a particular stone.
-----------

I'm still on the fence about buying a brilliancescope or not, so at the present time I wouldn't be able to answer this question for you. Perhaps some of the vendors might have experience with "trends" in this area.

A bit of research you could do on your own is go to sites which have brilliancescope results, plug the stones measurements into the HCA, and see how it's analysis compares with the posted brilliancescope results. I'd be curious what you come up with.
 

Colored Gemstone Nut

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Hey Richard- Great Idea. A sort of assignment. I will get back and post as soon as I run a gammit of stones through and compare them. In the HCA i notice that the pavilion angle in which stones exhibiting excellent fire and brilliance on the HCA fall between (40.4-40.9). I think 40.5 being the ideal pav angle for stones which are run through it receive the higher scores. I also notice that if the pav angle runs over the 40.9 mark it affects the overall score on scintillation just as dropping below a pav angle of 40.4 it affects the light return of the stone. In both categories light return and scintillation dropping going over or under the mark raises the overall score of the stones visual performance. Anyway thanks for the project & I'll post when I get done with my little homework assignment and any other observations I make.

How's the weather in your neck of the wood's. Haven't had a drop of snow here since the 24th of Dec. Temps. have been in the mid-40's very mild for these parts and a welcome change.

Jonathan? RockDoc? Garry? I'm waiting for some replies on my earlier posts. I'm here to learn.


Josh Rioux
Sitka, Alaska
 

Richard Sherwood

Ideal_Rock
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Sounds like you're the perfect man for the job. Have at it and I'll try to keep busy drinking wine or something while you're laboring.

It's been a little nippy here lately on the Sun Coast of Florida, with temperatures plunging down to the low 60's at times. I've actually had to pull out a sweater once or twice.

It's a tough life, but somebody's got to live it.
 

Garry H (Cut Nut)

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Hi Scorpio - there was not a lot I could reply too.
And it has been a busy day


I am interested in the results of your assignment.

Scintillation drops off on deeper stones as the amount of darkness reduces. The darknss is the head obstruction of light by an observers head.
Here is a little old article by our freind Beryl.
http://www.gemology.ru/cut/english/faceting/
 

barry

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Josh;

Interesting research project, indeed.
Working with Gary, SuperbCert lists the HCA
score for every one of our diamonds on-site,
including our Premium Cuts, making it
easy for you to compare these numbers
to our listed BScope results.

As Rich suggests, you're the perfect man for the job;
but while Rich is sipping wine in balmy Sarasota;
we're digging out from a 17 inch snow-blizzard
here in New York. Ouch!


Hi, Rich


Barry
www.superbcert.com
 

optimized

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Hi Josh,

). I found having a variety of sources to be very helpful in reaching a sort of "consensus estimate" of performance. Another nice thing about this method is that you can open the results for a few different stones (by right-clicking the link and selecting "Open in New Window") and clicking back and forth to compare individual aspects. It can get tough to keep track of all the windows, but in the end it made me more confident in my decision.

Btw, here in South Jersey we're digging out of about 20 inches of the white stuff, and it's still predicted to keep piling up in the form of snow mixed with sleet for a while longer (ouch is right, Barry!). However, to be honest I've always loved the snow so I'm not too upset by the stuff.


-Tim

[/u][/u]
 

Colored Gemstone Nut

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----------------
On 2/17/2003 10:27:31 AM optimized wrote:

Hi Josh,

I also think you've got a great research project going. I did a little bit of the kind of stuff you're talking about while I was looking for my diamond, and I found Barry's SuperbCert site to be an invaluable tool since it has both BrillianceScope Analyses and HCA results for all stones listed. I got in the habit of opening multiple browser windows and checking the stones through various sources (separate pages for: SC product page, Megascope report, BScope analysis, HCA, as well as Dave Atlas' AGA cut charts).

Hey Tim-Thanks for the advice. I too have the same research style as you do evaluating stones. I was not aware of Dave Atlas AgA cut charts, do thanks.

Hey Barry-I am using your site and Joonathan's site being the both of you have that information and b-scope results available. I graduated in Upstate New York and can remember how it could really dump on us.

It will take a while for me to run all the stones, but I should get back with you guys and the results in a couple days.

Thanks-Josh Rioux
Sitka, ALaska
 

Colored Gemstone Nut

Ideal_Rock
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Well Rich here's the first 40 stones I have compared. It is taking me quite some time but I plan to post more results as I go on and welcome comments from anyone as to inquiries or suggestions and info from those in the trade that know their stuff. Out of the first 40 stones. Charts are below. Numbers tp the right of the diamond selection is just the stone count (1-40). To the right of the HCA is the carat weights. 36/40 stones approx. 90% of stones which received low (low meaning good) HCA scores between .5-1.5 and were rated excellent in all 3 categories of fire, brilliance, & scintillation on the HCA also scored very-highs across the board in all 3 categories of the GEMEX brilliance scope. Those 3 categories being rated for WHITE LIGHT,COLORED LIGHT, & SCINTILLATION. There are exceptions to some stones which do not receive excellents in all categories of the HCA still rate high in all 3 categories of the b-scope. The HCA has been taunted as a good tool for doing a preliminary search for possible candidates for stones which would perform well. Knowing what the HCA results are and having the b-scope results to compare has given me the preliminary data I have compiled so far. It looks as though the stones listed so far do have a direct correlation with being good performers on the b-scope and also having the high HCA results is leading me to believe more times than not a stone which does well on the HCA will perform well on the b-scope. There are those exceptions in various stones which exhibit high HCA scores, but perform mediocre on the b-scope which leads me to my next question. The HCA is a tool and with that in mind what affects the light return of the stone in all 3 categories. It is not just the ideal dimensions, but can it be the placement and variances in the minor facets on the top of the stone. Any question or comments..Please add to the thread. I would like this to be an ongoing study and thread in which everyone can answer some unanswered questions about some of the discrepencies between the different tools being used to evaluate performance. Don't get me wrong I have an urge to really know what affects the light return and am not at all trying to find what might be wrong in the current tools used. So if lights being reflected out the top of the stone if there are some small variances in facets and placement of those facets can this affect how strong the light is being emitted? Thus affecting the b-scope results.
Let me Know some more input and I'll be adding to my data of already listed stones.
Peace-
Josh Rioux
Sitka, Alaska

TIm Posted my chart thanks tim a million!!!!





 

Colored Gemstone Nut

Ideal_Rock
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eeeeek-My chart didn't turn out. You guys have the data you need though.

Josh RIoux
Sitka, ALaska
 

Garry H (Cut Nut)

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Great work S.

Perhaps if you send the file to Leonid he can put it up in a readable format?

I would like to have some links to the stones that are anomolous if possible.

Some my be what we class as 'Girdle cheats'. We are writting an article about this at present - it is more than just minor facet variatio - it is something we think is coming out of Israel that is deliberately designed to get an AGS 0 cert, even though the girdle is way too thick, and upper girdle facets are up to 5 degrees steeper than you would expect.

Cheers
Garry Holloway
 

Garry H (Cut Nut)

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hmmm

Unless you can get a good cross section of data from excellent and poor stones, this is not going to be a very insightful comparison. Especially since the only real variance in your data is Briliancescope "scintillation" - I have never been able to understand what they measure in this feature.

You are trying to make a chart the equivalent of the stock market during the tech bubble a few years ago. You could prove lots with such data that would be meaningless.

Perhaps if you could break the VH into VH 1,2 and 3 - then I could give you a more complex HCA that scores each factor numerically. But it would be a lot more effort S.
 

aljdewey

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----------------
On 2/20/2003 4
7:22 AM Cut Nut wrote:
hmmm

Unless you can get a good cross section of data from excellent and poor stones, this is not going to be a very insightful comparison.

Perhaps if you could break the VH into VH 1,2 and 3 - then I could give you a more complex HCA that scores each factor numerically. But it would be a lot more effort S.----------------
I agree with Cut Nut.....in order for the data to be meaningful, it would need to include poorly cut stones as well....stones known to have poor cut proportions which score poorly on the HCA and their corresponding b-scope results.

I'm not sure there's a way for Josh to gather this data, though. The few sites that provide B-scope results don't display poorly cut stones. The only way to get this would be for those who have B-scopes to intentionally scan some poorly cut stones for educational purposes only (Jonathan?) and to post B-scope results for them. Knowing how busy Jonathan and other vendors are, I'm not sure if they'd have the availability to contribute the raw data.

I'd really be interested in the result, though. Great effort on the table, Josh...I admire your curiosity.
 

optimized

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Funny you mention that "VH 1,2 and 3" idea. That was my first thought when I read the chart as well. Very difficult to compare results when almost all of the diamonds rate "vh" in so many categories.

Similarly, it would be nice if it were possible to get some more specific information from the HCA as well (no Garry, you aren't immune either
). My impression from playing with the HCA indicates to me that the overall score is reached by computing separate values for each factor, then adding them together for a final score (e.g. .5 brilliance, .5 fire, .5 scintillation = 1.5 TIC, whereas a .8 brilliance, .2 fire, .5 scintillation = 1.5 FIC, etc.). Garry may of course correct me if I'm wrong, but it seems to work that way. It would be nice to have the individual values for the sake of this exercise, eh?

Being the type of person that avoids doing any "real work" on my days off, I've taken some time to throw together a possible "example scale" of a more detailed BScope analysis for possible use (if Josh sticks with the project). How 'bout something like this?

Bscope scale1.gif
 

optimized

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And, a sample analysis:

White Light: V3
Colored Light: V3+
Scintillation: H/V

sample1.gif
 

optimized

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Garry,

I know what you're saying by the statement, "...the only real variance in your data is Briliancescope "scintillation" - I have never been able to understand what they measure in this feature," but I've often wondered the same thing about the HCA's "scintillation" rating.
My understanding is that the physical cut proportions of the actual facets (longer/shorter pavilion mains, etc.) have the biggest impact on scintillation, which is impossible to incorporate into the HCA using currently-available data. I personally have definitely noticed differences in scintillation in diamonds looking at the BScope animations so I can see how the data is useful, but I guess there's a point at which one must just sort of make an educated guess, eh?

aljdeway,

I agree that there's some work involved in finding the "poorer" stones to judge the lower scores by, but Jonathans site has quite a few stones that don't rate "VH" in ALL three categories (i.e. two VHs and one H, etc.) so it might be possible to extrapolate pretty useful data from looking at those lower scores.

Josh,

As you can probably tell, I'm really interested in your project. Keep up the good work! If I might make a suggestion, you might want to edit your "chart" post and remove all those stats. It's kind of a pain to have to scroll a mile to reach the next post, and I think my chart does justice to your great research (I hope).


-Tim
 

Garry H (Cut Nut)

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Tim you are right about the scoring system, but you are wrong abouut it being kept a secret.

All the secrets have always been displayed at www.diamond-cut.com.au in enormous detail.

The reason we do not put each factor score down is users become too anal. We would like to use a bar method and no numbers either for the total score as well. What do you think?
 

billyb

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Wow this looks like a great project! I'm surprise more studies like this haven't been conducted before (ie by Gemex). Or maybe they have but just haven't been published for us to see.

scorpionrioux did a good job collecting that data and the way optimized displayed it was very heplful. I agree that more data on poor performing stones is required.

I really like the way optimized 'tuned' the BrillianceScope data (they should pay you for that! hehe). I'm curious as to how the BrillianceScope charts actually get generated. There must be some sort of numerical score associated with each of the 3 measures. It appears that the blue bars are all of the same width (except when its a VH3+) and so if you label the scale from 0 or 1 to 10, you could place a value on the middle of the blue bar and end up with 3 numerical scores. Having numerical values for all 3 HCA components and all 3 BrillianceScope components would allow for even finer correlation analysis between the two. Now, what will it take to tweak/hack the BrillianceScope to spit out numbers instead of a blue bar? I imagine not much but I'm just a hopeful consumer who has never used a BrillianceScope nor seen one in person. But oh what fun would that be!! How much do they cost (ballpark) anyways??

Personally, I prefer the numbers to the bars...
 

optimized

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Garry,

I never thought it was a "secret," (did my post sound like I did?). I was just pointing out how nice it would be to have the individual numbers for this exercise.
I also agree that there is the potential for folks to get too anal about the numbers (ME! ME! ME!), but for this exercise it would be a useful tool....

-Tim
 

Garry H (Cut Nut)

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Tim I have offered to send a desk top version of HCA to Scorio


This gives all the #'s

We have not wanted to sell it as it is difficult to get back to all the users when we make changes and adjustments.

But its more accurate data should be part of the subscription service that everyone should be clamouring and emailing Leonid about - it will make diamond buying much quicker and easier.
 

Colored Gemstone Nut

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Garry a desk top version of the HCA would be great for me to use..more info please...

Tim-I don't know what say except thanks. I don't know how you retrieved the data from the scrabbled muck on the screen but you did it great job. My initial intentions were to include either the sarin data/megascope readings with the stones I am comparing to also get a general idea if the proportions have a part in affecting the b-scope results. I like the idea of having the 3 classes of rating in each category for the b-scope. I will persist in collecting the data and Tim I would like to ask you how you made that chart and posted it in the size so it would fit when you posted it. My next results which will be of more stones added to the previous list will include the scoring of vh1,vh2,vh3 etc...

Garry: I also thought that the comparisons in this study needed to reflect stones which scored low on the high on the hca but low on the b-scope. I know that the 2 posted sites in which I am comparing stones are posting the best stones in all categories. Take a 1,000 stones that were graded and post the best 200 which only fall in certain parameters. I too agree it is important to list those other stones who don't perform well on the b-scope but perform well on the hca so we can really get down and scrutinize what truly affects the b-scope reading rather than just assuming a stone that has a high hca score will perform high too on the b-scope.

Tim-Please don't hesitate to contact me via email on any suggestions you have for the [email protected]

Jonathan/AKA Rhino-Can you please send me as much data and b-scope readings on poor performs on the b-scope with high hca scores. I am using the stones on your site currently along with the stones on Barry's site in making the initial comparisons as part of this research but by the looks of things you guys are posting your top stones, we need them all.

Richard-How are you doin? Haven't heard a word back from you on this post. Are you busy soaking up that florida sun?

Thanks a million and get back to me. I will be posting more results as I evaluate and chart the different stones.

-Josh RIoux
Sitka, Alaska
 

Colored Gemstone Nut

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----------------
On 2/20/2003 4
7:22 AM Cut Nut wrote:
hmmm

Unless you can get a good cross section of data from excellent and poor stones, this is not going to be a very insightful comparison. Especially since the only real variance in your data is Briliancescope "scintillation" - I have never been able to understand what they measure in this feature.

You are trying to make a chart the equivalent of the stock market during the tech bubble a few years ago. You could prove lots with such data that would be meaningless.

Perhaps if you could break the VH into VH 1,2 and 3 - then I could give you a more complex HCA that scores each factor numerically. But it would be a lot more effort S.----------------
Hey GArry-I will add this to the comparison charts. What do you think about adding the megascope data/ sarin data along with the changes and the addition of the poor performing stones. Any other suggestions would be insightful.

Josh RIoux
Sitka, ALaska
 

Garry H (Cut Nut)

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I tried to email you Josh, but it bounced.

Here is the message:
I would like to know first if you will be able to get some decent representative Brilliancescope and proportion data.

Also Josh I hope you would understand:
I will also need some assurances before I give you a copy of HCA - it would be unprotected and could be passed on to anyone as we have no codes or protection built in.

Finally when you do this study it should be conducted with no set plan to seek or find anomalous data between the two systems - it should include all available data so that exceptions are seen in context.

regards
Garry Holloway
 

Colored Gemstone Nut

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----------------
On 2/20/2003 11:54:23 PM Cut Nut wrote:
I tried to email you Josh, but it bounced.

Bummer Garry. Did you try [email protected]tmail.com

Here is the message:
I would like to know first if you will be able to get some decent representative Brilliancescope and proportion data.

The data I am using off the 2 sites is from the gem-ex brilliancescope and scanned and posted sarin data & megascope data

Also Josh I hope you would understand:
I will also need some assurances before I give you a copy of HCA - it would be unprotected and could be passed on to anyone as we have no codes or protection built in..

I wouldn't want to do anything of the sort Garry. It would be a good tool and I would value having a copy. I would also give you my word I wouldn't pass it on & would strictly be using it for the purpose of the study.

Finally when you do this study it should be conducted with no set plan to seek or find anomalous data between the two systems - it should include all available data so that exceptions are seen in context.

I understand that would taint the data and would not deem the study as an un-biased one. The data will be collected in a concise way and will be stated as is with no alterations. I am leaving any conclusions on the final analysis of the study up to you or any other qualified professional in the field. I see myself as a person with great curiousity and at the same time am willing to do the leg work in collecting the data and will leave it up to you guys elaborate on the findings. It will hopefully provide a little more foundation for me in the search of what the data and facts conclude with the expert opinions added.

regards
Garry Holloway

Thanks Garry!

-Josh


----------------
 
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