41 degree pavillion angle

[Serg]

Date: 7/15/2007 2:42:41 PM
Author: Pyramid
Serg

I think what Paul was referring to is that this particular diamond and this particular cutter Jonathan sometimes uses cuts very tight diamonds, which apparently can be seen from the Helium report which is available in the link in Jonathan''s post a few pages back.

Pyramid,

Michael point: If you cut 41/34 or 40.75/34.5 , Final result mostly depends from your skills( Not from set proportion )
It is not same for 40.75/34.5 and 40.5/35.

It is constructive point of view. I do not see any constructivism in Paul post.

 

[Cehrabehra]

Date: 7/15/2007 2:42:41 PM
Author: Pyramid
Serg

I think what Paul was referring to is that this particular diamond and this particular cutter Jonathan sometimes uses cuts very tight diamonds, which apparently can be seen from the Helium report which is available in the link in Jonathan''s post a few pages back.

and ultimately it doesn''t matter if 99% of butts look big in those jeans as long as YOUR butt looks fantastic!!

 

[He Scores]

RE: Personally I find the minutia of all of this quite interesting - but to what extent is this an eye visible issue to the consumer?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


My personal research of 50 diamondtaires indicated that half of them disagreed on two stones that were 6% apart.

In other words, when asked which stone was cut better, some said an 862 and the others said 920.

Other findings were when asked to view stones to determine which was cut the best, I believe 90% first viewed the stone with a loupe rather than the naked eye. I did not restrict or instruct how the stones were to be viewed like in the GIA observation tests. When I asked AGS about observation tests, they don''t conduct them other than the feedback from their lab workers.

Bill Bray
Diamond Cutter

 

[michaelgem]

Date: 7/15/2007 3:02:50 PM
Author: Serg

Pyramid,

Michael''s point: If you cut 41/34 or 40.75/34.5 , the final result mostly depends upin your skills( Not from the proportion set )
It is not same for 40.75/34.5 and 40.5/35.

It is constructive point of view. I do not see anything constructive in Paul''s post.

Thank you Sergey,

I too saw nothing constructive in Paul''s post, only a dismissive condescension. That is not an effective form of debate, especially when no substantive discussion follows.

However, what the AGS, GIA and MSU charts and I have demonstrated and Sergey''s photorealistic imagery has backed up is not changed or negated under reductions in symmetry. Both these diamonds with identical beauty and optical performance will degrade in performance in a similar manner as symmetry is reduced.

In addition, there is no need for me or anyone to reach Paul''s skill level of cutting. There are literally thousands of Indians, Chinese and Russians who are now cutting optically symmetrical super ideals with the same precision as he does with the aid of today’s ever improving cutting technology. Who do folks on Pricescope think is cutting all these premium make, optically symmetric diamond’s they buy for cut rates through Internet venders?

Ideal regards,

Michael

 

[Serg]

re:Well, Michael, now that you think that you have proven this point, can you try and cut both these theoretical examples?


Well Paul,
I will order these two diamonds for MSS. It will stones 12th and 13th in list http://www.octonus.com/oct/mss/

 

[Garry H (Cut Nut)]

Date: 7/15/2007 8:50:37 AM
Author: Pyramid

Date: 7/15/2007 8:32:54 AM
Author: michaelgem








If Sergey adjusts the crown angle somewhat along the ''axis of Ideal'' , that is, as he increases the pavilion angle from 40.75 he inversly adjusts the crown angle, he will find similar path length histograms. That is what the AGS charts, the GIA charts and the MSU charts indirectly imply.


I think it is really sad that someone with as much time and experience on PriceScope as Pyramid, can talk herself out of what is argueably an unbeatable beauty.

Thanks michaelgem

Not getting into any technicals here because I don''t know about it, I do understand what you are all writing and what you all mean but I am a non knowing person regarding talking about any of it myself.

However the inverse crown and pavillion angles, I believe was something that Garry Holloway found out I believe long before GIA AND AGS and yet they are the people always quoted for it. I think they ought to stand up and attribute that to Garry

, ha just speaking from a consumer point of view and I like to see the people get the praise for it in the same way Morse should if his diamond angles were better than Tolkowskys. Garry says in the tutorial that his finding this out was just ''common sense'' but I put that down to his Australian way of talking a bit like the British we don''t brag enough, but Garry it was not common sense because otherwise the diamond angles put up by AGS etc would have accounted for it and they didn''t in the past. So I do think Garry needs to be recognized for something which only he thinks is ''common sense'' because of his great mind.

I am not really talking myself out of it, but I am sort of piggy in the middle here when there are two very well read and practiced people with differing views, yourself and Brian the Cutter, not to mention other gemmologists and Garry''s (who is a gemmologist too) HCA measuring the diamond as lacking even if just a small amount in Fire and Scintillation from one which receives 4 EXs on his HCA although I know he has said himself the tool is for a first rejection and not to put too much into the 4 EXs part of it.
Pyramind thanks for the kudos, but HCA is a rejection tool - and you are using it as a grading tool on a diamond with excellent sym and perfect proportions.
So anyway, will GIA and AGS recognise Garry Holloway for the inversion thing which he told the public about before GIA and AGS even knew about it?

Older pre lab cutters ''box'' type cut grades knew about it too, and Peter Yantzer acknowledged it after I gave him a DiamCallc demo showing why a 25 degree crwon angled stone could be very beuatiful with a deep enough pavilion, but thx Pyramid.

 

[pyramid]

Date: 7/15/2007 3:02:50 PM
Author: Serg

Date: 7/15/2007 2:42:41 PM
Author: Pyramid
Serg

I think what Paul was referring to is that this particular diamond and this particular cutter Jonathan sometimes uses cuts very tight diamonds, which apparently can be seen from the Helium report which is available in the link in Jonathan''s post a few pages back.

Pyramid,

Michael point: If you cut 41/34 or 40.75/34.5 , Final result mostly depends from your skills( Not from set proportion )
It is not same for 40.75/34.5 and 40.5/35.

It is constructive point of view. I do not see any constructivism in Paul post.

Serg

I see what you mean, I was just taking what Paul had said as all that had been proven was that a very tight stone may not look dark or as bad as a lesser cut stone of the same 34/41 and that a point had not been proven that 34/41 was in general as good as 34.5/40.75 or 34.7/40.8 and so in general the 41 pavillion was still of concern most of the time.

 

[pyramid]

Garry, stop topling yourself off the pedestal

 

[Serg]

Date: 7/15/2007 4:10:34 PM
Author: Pyramid

Date: 7/15/2007 3:02:50 PM
Author: Serg

Date: 7/15/2007 2:42:41 PM
Author: Pyramid
Serg

I think what Paul was referring to is that this particular diamond and this particular cutter Jonathan sometimes uses cuts very tight diamonds, which apparently can be seen from the Helium report which is available in the link in Jonathan's post a few pages back.

Pyramid,

Michael point: If you cut 41/34 or 40.75/34.5 , Final result mostly depends from your skills( Not from set proportion )
It is not same for 40.75/34.5 and 40.5/35.

It is constructive point of view. I do not see any constructivism in Paul post.

Serg

I see what you mean, I was just taking what Paul had said as all that had been proven was that a very tight stone may not look dark or as bad as a lesser cut stone of the same 34/41 and that a point had not been proven that 34/41 was in general as good as 34.5/40.75 or 34.7/40.8 and so in general the 41 pavillion was still of concern most of the time.

re:that a point had not been proven that 34/41 was in general as good as 34.5/40.75 or 34.7/40.8

Did anybody prove opposite statement?
What is recognized proof( recognised rules for such proof) of such statement.I sure If you or Paul will explain such rules alot of people could proof it.
But if such rulles are absent Does anybody have rights to say "It had not been proven yet"? ( Is correct to say try cut, it is just theory, how are many diamonds did you see,..)?

 

[pyramid]

Date: 7/15/2007 4:21:20 PM
Author: Serg

Date: 7/15/2007 4:10:34 PM
Author: Pyramid

Date: 7/15/2007 3:02:50 PM
Author: Serg

Date: 7/15/2007 2:42:41 PM
Author: Pyramid
Serg

I think what Paul was referring to is that this particular diamond and this particular cutter Jonathan sometimes uses cuts very tight diamonds, which apparently can be seen from the Helium report which is available in the link in Jonathan's post a few pages back.

Pyramid,

Michael point: If you cut 41/34 or 40.75/34.5 , Final result mostly depends from your skills( Not from set proportion )
It is not same for 40.75/34.5 and 40.5/35.

It is constructive point of view. I do not see any constructivism in Paul post.

Serg

I see what you mean, I was just taking what Paul had said as all that had been proven was that a very tight stone may not look dark or as bad as a lesser cut stone of the same 34/41 and that a point had not been proven that 34/41 was in general as good as 34.5/40.75 or 34.7/40.8 and so in general the 41 pavillion was still of concern most of the time.

re:that a point had not been proven that 34/41 was in general as good as 34.5/40.75 or 34.7/40.8

Did anybody prove opposite statement?
What is recognized proof( recognised rules for such proof) of such statement.I sure If you or Paul will explain such rules alot of people could proof it.
But if such rulles are absent Does anybody have rights to say 'It had not been proven yet'? ( Is correct to say try cut, it is just theory, how are many diamonds did you see,..)?

I can't answer for Paul but I think he is still on his side of the fence and the scientific people are still on their side. I think he just got a bit frustrated with it all. Maybe a Cutters way of proving it would be to produce two stones cut to prove their point whereas scientific is more to do with words. Maybe the Cutters can see something about the diamond that Scientific people cannot in the same way they would not maybe know your side.

 

[michaelgem]

Date: 7/15/2007 1:51:29 PM
Author: Pyramid
Thanks Michaelgem, oh I have always realised that Sergey here is brainy and certainly something that most people could never obtain in their lifetime, I also know that you know a lot about the subject yourself as does Brian and all the Cutters. I am reading and appreciating and know that you are all getting something from this too, it is not just about one diamond, this one, but about Pricescope and the information that those who know about it can get from each other, and those consumers like myself can learn a bit about it, if we are interested, even though we will never know the intracies without education in the subject at a higher level and maybe even a level we could never obtain.

I have spent almost 10 years findiing ways to simplify for my ciients, folks like you, why the Super Ideal is the most beautiful and highest performing of round brillinat cut diamonds. A read of just these two articles, http://www.acagemlab.com/articles/sweetspot/index.html and http://www.acagemlab.com/articles/DiamondEye.htm , will get you to that higher level, which is well within your reach should you choose to grab it

I appreciate what everyone has written here, very very much, and that is from both sides of the fence. Maybe there is no right like many things in life.

Sorry, if anyone thinks there is no right to the issues and points discussed here, they have not studied the evidence well enough. If I were a judge talking to the jury, I would council them to go back and restudy the body of evidence presented, and don't return until you have reached a verdict.

Best wishes,

Michael

 

[JohnQuixote]

Michael,

GIA EX is skewed faaar to the steep/deep (I trust you won’t contest that).Serg showed how much saturation increases in those combinations so I suggest it's not practical to include them in your chart of 'sweetness.'

It's also strange that you plotted AGS0 & AGS1 on your chart. That made the data look centralized but I submit it's not.

For a different perspective I placed the yellow block over configurations not included in the 2006 AGS cutting guidelines (what they are telling manufacturers to cut and not to cut). As you see 41/34 moves back to the edge & Tolk is more centralized in this scenario.

The AGS PGS grades more liberally after stones are cut so the yellow may be a bit conservative downstream but not by much. I have yet to see a 41/35 receive 0 light performance on a lab DQD.

 

[WorkingHardforSmallRewards]

What would it cost for you to buy a ticket to the states?

It sounds to me like it is time for you and your hubby to take a vacation, and dedicate three afternoons/evenings of it to diamond shopping at the vendor of your choice.

 

[pyramid]

Date: 7/15/2007 6:45:00 PM
Author: WorkingHardforSmallRewards
What would it cost for you to buy a ticket to the states?

It sounds to me like it is time for you and your hubby to take a vacation, and dedicate three afternoons/evenings of it to diamond shopping at the vendor of your choice.

Not convenient at the moment. I am starting to think though that maybe the 34/41 is not so bad. I do think that cone thing I went on about was the smaller table because in the UK we are not used to seeing tables smaller than 57.5 or maybe it is 60s we see here, not sure, but it is smaller than my diamonds and any diamonds I have seen around on other people some who I know could afford very expensive and probably bought from highend places. The image Serg put up with 57.5 table looked more normal to me, so it is I believe just what I am used to seeing on people and in jewellers displays. I don't see any colour much at all in the diamond and has never bothered me as I said. I don't think I see any difference to do with under the table being darker to the stars and kite facets. There was beautiful fire and movement when I did see it in the sun for about 5 minutes so I think I just need to decide now what I want to do. If I was not getting this one I would not be going to USA anyway because I would have to look for another in this unusual weight which could take a while or save up more money to get 2 carat range if they are more plentiful in the H colour. I do not want to go below H so I am stuck there and I will not go below VS1 clarity. So I am still uncertain and just need a few days to make up my mind about keeping or returning the diamond. These conversations though between the experts I am finding interesting even if it was not to do with the diamond I am considering. As I have thought before there will always be another diamond and I have learned over 5 years here not to get too stuck on the one.

 

[Cehrabehra]

John, love your creative file naming, naughty boy!

 

[WorkingHardforSmallRewards]

I hear you pyramid. One day when I purchase a larger diamond for my wife I will be just the same as you. In fact, even with my small diamond I would probably go ahead and keep looking and redefining exactly what I want..higher crown angles, lower LGF, etc, but you know how it is...proposals can't be postponed forever for the minutia, or I may well miss out on the most important element-her! but I have a feeling once the clouds clear up you aren't going to want to let it out of your hands. but I'll be waiting to see! and even if you do send it back, take a few pictures for the fire thread, those are always a blast to see.

 

[strmrdr]

Date: 7/15/2007 6:20:47 PM
Author: JohnQuixote

Michael,

GIA EX is skewed faaar to the steep/deep (I trust you won’t contest that).Serg showed how much saturation increases in those combinations so I suggest it''s not practical to include them in your chart of ''sweetness.''

It''s also strange that you plotted AGS0 & AGS1 on your chart. That made the data look centralized but I submit it''s not.

For a different perspective I placed the yellow block over configurations not included in the 2006 AGS cutting guidelines (what they are telling manufacturers to cut and not to cut). As you see 41/34 moves back to the edge & Tolk is more centralized in this scenario.

The AGS PGS grades more liberally after stones are cut so the yellow may be a bit conservative downstream but not by much. I have yet to see a 41/35 receive 0 light performance on a lab DQD.

yea but if you use the charts that Serg has generated from the pgs software it moves right back.
Basing anything on the charts is not supported by AGS.
They refused to generate and release new charts for this very reason.
A chart can not accurately show the AGS grades because it takes more than 2 axises to show anything.
So naughty naughty JQ and Michael.
and yes I am laughing my ack off.

 

[Ellen]

Hi Pyramid,

I just read through this thread.

lol


If you're wanting a different profile visually, then yes, you'd need a different stone.

I "think" I read somewhere in these 8 pages that you preferred brightness over fire (please correct me if I'm wrong). If that is the case, I don't think a, say, 34.5/40.8 is going to get you that....

If you aren't loving it just because you "think" maybe you shouldn't because of the PA, try and take a step back. Forget what numbers you have, and look at the stone. And really, get it out in as many different lighting situations as you can, let it show its stuff.

Our stones are very, very similar. I've probably read everything you have on 41 PA's. It was all rather interesting at first to see the differing opinions, but not so much now. I have had my stone for almost a year and a half. I know what it does (and doesn't) look like. I know it's stunning, my eyes tell me that. I have also read from those who do not prefer this PA, what a diamond should look like, behave like, across the board. All I can say is, well, mine does that. *shrugs*

I've also compared it to my ACA studs, which are also stunning, and cut to the more "cherry" specs. It's no less beautiful. At all.


So, I've not said all this to sway you into keeping it, but to give you a firsthand account of life with a 34/41. I hope I've helped, no matter what you decide.

 

[aljdewey]

What this all comes down to is ''analysis paralysis''.......fear of making a mistake, fear of not being able to trust one''s own eyes to see beauty. That''s truly sad.

I honestly don''t see why this comes as a surprise to anyone. THIS is exactly why Leonid was so adamant over the years about not contributing to an ''FUD'' climate.....instilling fear, uncertainty, and doubt. THIS is the backlash of doing that......folks being paralyzed with fear that they cannot trust their own eyes to judge what''s beautiful to THEM unless every manner of software and/or gadget validates their judgment. You can blatantly see it in Pyramid''s comments:

"it may just be that because of course I am not trained at all to look for tone"
"I think that is something I am maybe missing, remember I cannot speak fact here because I have no training."

Paul''s comment was spot on......"In this way, Rhino also needs to be very careful with the generalisation of his observations." Amen to that. This very instance is an example of how sweeping generalizations can bite you in the backside. Over the years, such generalizations have been made about a LOT of things. I''m afraid Rhino is now being bitten by the very beast he himself helped to create in the first place.

For years, he''s beat the drum on the ring of death and how 41 pavilion was where a stone could begin to have performance issues (as aptly illustrated in his comments quoted by John Q in this thread - I think his words were A LOT of stones). Now that he''s changed your mind, he''s suffering from having conditioned his pupils too well.

There is TREMENDOUS irony in reading some of Rhino''s comments in this thread to Brian.....

"consumers who are reading this are being led down a path that will lead them to false conclusions..."
"This blanket statement is misleading in the minds of consumers."
"(about infinitessimal measurements)...Some that have absolutely no bearing on the optical performance and some that do. It is our responsibility as gemologists to see and determine this if it indeed does."
"Your comments in this thread are scaring consumers out of diamonds akin to this which are nothing short of best of the best.."
"Are consumers being mislead by purchasing a diamond like this because your post certainly makes it seem like anyone considering such a stone is getting a 2nd rate diamond."


These comments are eerily almost verbatim to those made TO Jonathan on many past occasions when he (and others) made similarly broad statements on several issues. Waving the *warning/caution* flag on painted diamonds regardless of other attributes about the stone or how infinitesimal the painting degree, and causing several folks who were purchasing them to put the brakes on their purchases in fear of getting a 2nd rate stone. Waving the *warning/caution* flag on diamonds that score below a 1.0 on the HCA (leading folks to think that their 0.9 scoring diamond might be inferior). Waving the *warning/caution* flag on diamonds with a 40.6 pavilion.....it''s amusing to read this Rhino comment "41.0 instead of 40.9 darkens a stone?!?!" when such a concern was remarkably absent when the numbers were 40.7 and 40.6 pavilions instead. Interesting, no?

That said, it''s BEYOND grossly inaccurate for Rhino to point his finger at Brian''s comments in this thread and even TRY to suggest those comments will be the primary impetus affecting Pyramid''s decision. (....because she is certainly weighing heavy on your (Brian''s) words with respect to her purchase." Not even close. Her doubts caused her to initiate this thread.....before a single word had been uttered from Brian''s mouth, to begin with. Furthermore, Pyramid''s comments make it quite clear that she''s being significantly influenced by other posters (prosumers), NOT by Brian.

"I think I was believing the posters and then the vendors tell you it is so minute that it is okay and it is like well who do you believe."
"No it was not anything to do with what you (JQuixote) posted, it was more what posters had been posting in the past in threads."
"Yes I agree with you that the professionals cannot make distinctions, but when prosumers are saying 41 degree pavillion is bad and the only diamond fitting my parameters was great otherwise than the 41 degree pavillion and all I am finding is that this is a no no or ''not what I would prefer'' from other posters, it makes a person undecided."
"many posts from people asking the same question I had and when most diamonds by volume are being bought by people here in the 40.7-40.9 pavillion angle it makes you think there is something wrong with it although you know it is minute differences."

It bears pointing out that many of those posts she''s referring to (and those posters) were influenced Jonathan''s then-tutelage "cautioning" about 41 pav. stones, so he''s helped to make the bed he now finds himself lying in.

This type of scenario is precisely WHY I think Wink continues to be so impassioned in imploring Storm and others to be less absolute in sharing personal preferences. It''s fine to have an opinion, but presenting preferences in a way that appears to denounce other selections or inordinately weights the most miniscule of differences (many of which are ACADEMIC and not visually appreciable) can create a backlash that''s completely arbitrary, as has evidently happened in this instance.

Regarding Michael Cowing''s comment, "I think it is really sad that someone with as much time and experience on PriceScope as Pyramid, can talk herself out of what is argueably an unbeatable beauty." ..........well, Michael, I don''t think that''s what happening here at ALL. It''s absolutely the opposite. She''s LOOKED at the diamond with her own eyes and it doesn''t appeal to her, and she''s said it several ways.....

"....because I don''t feel I really love it and I think I like the look of a higher crown from the profile"
"....maybe that is why I don''t like the diamond but I could not put my finger on that being what it was just that there was something about it I didn''t care for..."
"...it may just come down to me not liking it with my own eyes and the crown height. When I opened the box if I had really liked it these details probably wouldn''t have mattered."
".....Really the bottom line is apart from the size and colour and clarity I don''t love the diamond."

.....and yet she''s afraid to trust her own eyes/judgment because others say "oh, that''s a top rate stone, blah blah." Almost everyone I know LOVES ice cream, and most would consider it a desireable treat, but that doesn''t mean EVERYONE has to love it, and those who don''t love it aren''t "wrong".

 

[JohnQuixote]

Date: 7/15/2007 7:14:00 PM
Author: strmrdr

Date: 7/15/2007 6:20:47 PM
Author: JohnQuixote


Michael,

GIA EX is skewed faaar to the steep/deep (I trust you won’t contest that).Serg showed how much saturation increases in those combinations so I suggest it's not practical to include them in your chart of 'sweetness.'

It's also strange that you plotted AGS0 & AGS1 on your chart. That made the data look centralized but I submit it's not.

For a different perspective I placed the yellow block over configurations not included in the 2006 AGS cutting guidelines (what they are telling manufacturers to cut and not to cut). As you see 41/34 moves back to the edge & Tolk is more centralized in this scenario.

The AGS PGS grades more liberally after stones are cut so the yellow may be a bit conservative downstream but not by much. I have yet to see a 41/35 receive 0 light performance on a lab DQD.

yea but if you use the charts that Serg has generated from the pgs software it moves right back.
Basing anything on the charts is not supported by AGS.
They refused to generate and release new charts for this very reason.
A chart can not accurately show the AGS grades because it takes more than 2 axises to show anything.
So naughty naughty JQ and Michael.
and yes I am laughing my ack off.

I did mention that (highlighted). I think it can be demonstrated that neither chart has teeth... Do two naughties make a nightie?

AGS is trapped 'twixt predictive scylla and charybdis right now. PGS generated charts assume impossible symmetry (too liberal) and the cut guides are confined to zero deductions (too strict). That doesn't mean you should toss them but it makes for different answers - and potential abuse by sellers. I've always erred on the side of caution and used the stricter guides when someone asks a predicted grade. It covers the fanny.

 

[aljdewey]

Pyramid, what it all comes down to is this:

Numbers help give us information on what a stone's elements are. They don't tell us whether or not we should find it beautiful. That's what our eyes are for.

Numbers PREDICT probabilities.....(probability that the stone will perform well, for instance). Probabilities are no substitute for actualities....which is what your eyes see and prefer.

No one should tell you what SHOULD appeal to you. The goal isn't to buy a diamond for others to approve of how perfect they think it is. The goal should be to buy a diamond that pleases you visually.

It's not as though you're choosing a vastly inferior make stone. These minute differences don't negate the fact that the stone is a top-performing stone. Whether or not the personality of THIS particular stone appeals to you.....no one can tell that but YOU. Trust your instincts. If you still don't like it, return it and pick something else. If you change your mind and decide that it does appeal to you, keep it.

You really can't make a "WRONG" choice here. Some people prefer fancy stones over rounds. Some people prefer AGS2 stones over AGS0. Same is true of food......while most people consider escargot and foie gras delicacy foods, that distinction doesn't compel me to like either of them, and I don't. It's ok not to like what others like, and it's ok to like what others might not.

There is NO "right" answer other than this: buy what your EYES like!

Good luck to you.

 

[hoorray]

Hi Pyramid,

I''ve read through this thread with good interest. The technical discussions are very interesting, expecially since they are in the context of the stone you just purchased. It seems to me that at least one aspect of the stone that you are grappling with is the "mind perfect" side of it. I completely uderstand it. My story follows -- I hope you don''t mind my interjecting it.

DH and I bought a similarlly expensive upgrade stone for me shortly after we found PS. We learned about the HCA, H&A, PA, CA. table size, super ideal, etc., but unlike you had no real experience with it. We picked a stone, got PS prosumers and experts input, looked at it in person but without others to compare it to, and bought it. The more I read on PS, the more I started to sweat the 35 degree crown angle. The Pavilion is 40.8, but I worried about the steepness of the crown angle. And, heaven forbid, I have no stats on the LGFs -- just an approximate guess from more reading. I worried that it wasn''t "the best" cut that I could get afterall. Little by little, I started to realize that my stone is in a class by itself compared to all the other stones I see around. People -- especially women-- comment on the beauty of my stone regularly. Several have asked me to help them find their upgrades or help with other purchases. One friend is thinking about trading in her cushion to get the sparkle of my stone... Once I quit focusing on the specs of the 35 degree CA, I found love my stone, and know all of it different personalities. Like all good PSers, I keep it clean, so I don''t run the risk of Garry''s "dirty stone" syndrome. I don''t know if it would apply, but have decided not to even try to figure that out. Just one more thing to worry about. I need a new appraisal, but really don''t want to hear anything that I would consider a negative about my stone. I don''t want the mind clean thing to interfere again.

The lesson learned I would tell you is to step back from the minutia that the cutters and scientists HAVE to think about, and think about you and how this stone looks to you and on you. Try to ignore what may be technical warts in your mind, and just focus on how it looks... I know you are trying to do this and are sorting out some of the "looks" issues, not just the specs, so if you still don''t love it based on those, send it back.

Good luck -- you need to feel good about this stone -- it makes it so much more fun...

 

[michaelgem]

John,

Date: 7/15/2007 6:20:47 PM
Author: JohnQuixote


Michael,

GIA EX is skewed faaar to the steep/deep (I trust you won’t contest that).Serg showed how much saturation increases in those combinations so I suggest it's not practical to include them in your chart of 'sweetness.'

It's also strange that you plotted AGS0 & AGS1 on your chart. That made the data look centralized but I submit it's not.

For a different perspective I placed the yellow block over configurations not included in the 2006 AGS cutting guidelines (what they are telling manufacturers to cut and not to cut). As you see 41/34 moves back to the edge & Tolk is more centralized in this scenario.

The AGS PGS grades more liberally after stones are cut so the yellow may be a bit conservative downstream but not by much. I have yet to see a 41/35 receive 0 light performance on a lab DQD.

If you can carve out time to read the article, you will understand better why 41 is dead center of the Ideal sweet spot for pavilion and why 40.75 is closer to the edge. I can make the case for venturing +- .4 degrees from 41 with appropriate crown angle adjustments and Tables within 2 to 3 percent of 56%. If you venture .4 degrees less than 40.75 I can make the case that you have fallen out of the Ideal category. If you go that shallow on pavilion and stay along the axis of ideal, you would need about a 37-38 crown angle to avoid too much head obstruction and get similar performance.

As far as 41 35 goes, those angles are dear to my American heart, as those are the angles attributed to American Henry Morse by Frank Wade, a top advisor to AGS and GIA founder, Robert Shipley. Wade's work published 3 years before Tolkowsky's was what Tolkowsky was referring to when he noted in Diamond Design that American writers credit Henry D. Morse with first cutting for "maximum brilliancy". The angles that Morse first discovered that were said by American writers like Frank B. Wade (1916) and Herbert Whitlock (1917) to yield an “ideal brilliant” had a range that centered on a 41° pavilion and a 35° crown.
Because the old guideline charts made this combination an AGS 2, I asked for Peter's input. He ran the numbers through the PGS software and got an Ideal 0. Since then the Russian cut study group has published charts indicating that the new Ideal 0 sweet spot is quite similar to the old guidlines 0 + 1. This was fortuitous, as the accordance I had uncovered remained intact and correct.

I haven't the time or energy to debate this now, but I have reason to believe that the beauty and light performance of the 41 35 is in some important respects superior to Tolkowsky's 40.75, 34.5. I know that many Tolkowsky purists take offense at what they likely perceive as heresy, but Tolkowsky did not see it that way. Remember the five diamonds he used as examples of maximally brilliant diamonds? They had pavilion angles from 40° to 41°, and crown angles from 33° to 35°.

So please read my case as I carefully laid it out in my short monograph. Then if you are still inclined, you can proceed to burn me at the stake.

Ideal regards,

Michael

 

[michaelgem]

style="WIDTH: 99%; HEIGHT: 197px">Date: 7/15/2007 7:53:10 PM
Author: lop
Hi Pyramid,

DH and I bought a similarlly expensive upgrade stone for me shortly after we found PS. We learned about the HCA, H&A, PA, CA. table size, super ideal, etc., but unlike you had no real experience with it. We picked a stone, got PS prosumers and experts input, looked at it in person but without others to compare it to, and bought it. The more I read on PS, the more I started to sweat the 35 degree crown angle. The Pavilion is 40.8, but I worried about the steepness of the crown angle. And, heaven forbid, I have no stats on the LGFs -- just an approximate guess from more reading. I worried that it wasn''t ''the best'' cut that I could get afterall. Little by little, I started to realize that my stone is in a class by itself compared to all the other stones I see around. People -- especially women-- comment on the beauty of my stone regularly. Several have asked me to help them find their upgrades or help with other purchases. One friend is thinking about trading in her cushion to get the sparkle of my stone... Once I quit focusing on the specs of the 35 degree CA, I found love my stone, and know all of it different personalities. Like all good PSers, I keep it clean, so I don''t run the risk of Garry''s ''dirty stone'' syndrome. I don''t know if it would apply, but have decided not to even try to figure that out. Just one more thing to worry about. I need a new appraisal, but really don''t want to hear anything that I would consider a negative about my stone. I don''t want the mind clean thing to interfere again.

Lop,

If your table size is within 3% of 56%, and the other 4 defining parameters are reasonable, you are in the heart of the AGS Ideal sweet spot, right along the "axis of Ideal". That would explain all the complements. You will aslo encounter less darkness because of reduced head obstruction compared to 40.75 and 34.5. This is part of what I alluded to in my previous post about Morse''s 41 35 American Ideal combination.

No worries.

Michael

 

[WinkHPD]

Date: 7/15/2007 6:45:00 PM
Author: WorkingHardforSmallRewards
What would it cost for you to buy a ticket to the states?


It sounds to me like it is time for you and your hubby to take a vacation, and dedicate three afternoons/evenings of it to diamond shopping at the vendor of your choice.

What a great idea, only Antwerp is just a short hop to Brussels and a $5 bus ride to Antwerp. There you could get to see the stones from many factories before they ever come to the states.

Wink

 

[WorkingHardforSmallRewards]

Date: 7/16/2007 12:11:04 AM
Author: Wink

Date: 7/15/2007 6:45:00 PM

Author: WorkingHardforSmallRewards

What would it cost for you to buy a ticket to the states?



It sounds to me like it is time for you and your hubby to take a vacation, and dedicate three afternoons/evenings of it to diamond shopping at the vendor of your choice.

What a great idea, only Antwerp is just a short hop to Brussels and a $5 bus ride to Antwerp. There you could get the stones from many factories before they ever come to the states.


Wink

Are you serious or joking?

 

[WinkHPD]

Serious, only I edited my post to read that she could get to see the stones rather than get. Also I see I should have edited it to say London is only a short hop to Brussels, darn I hate it when I miss stuff like that...

I don't think London is a very long flight from Brussels, but I could be wrong, it certainly is not as long as the flight from Boise.

About the $5 bus ride, that is what it cost me the last time I was there, could be more now that the $ is in the toilet.

Infinity Paul is there and several times a year, Brian the Cutter. I don't know if Jonathon goes there yearly or not but Pyramid could coordinate with any of them to see stones not only from their production, but the production of others as well. Then she could look at many stones side by side to see what she really likes!

Wink

 

[WorkingHardforSmallRewards]

Well geez, if this one is going back that sounds like the def route to take. a 2-5 year enterprise and ten's of thousands of dollars sounds like a special enough occasion to merit it already, and the cost would no doubt be a fairly small % increase when compared to the total ring cost. Go for it pyramid! Just make sure you let wink finish up the transaction for you if at all possible

but you know how it is...if somebody else's jeans make your butt look better...can't argue with that...

 

[Serg]

Re:Serg showed how much saturation increases in those combinations so I suggest it''s not practical to include them in your chart of ''sweetness.''

John,
I did not show it. I showed How saturation COULD depends from proportions.
Result depends from spectrum. For some spectrum such difference in proportions is not importnant at all.

 

[strmrdr]

Serg,
Can you change the lgf% from 75% to 80% keeping the c/p combo the same and post the average light path for 41/34 and 40.75/34.5 for each?
I would be very interested in seeing the results.