a different opinion on AGS 0 princess cuts

[Garry H (Cut Nut)]

A few comments:

1. I find the ideal-scope is still easier to use for rejection of fancies, but then I look at the pile of “possibles” with the ASET. And I rotate the stones – it is not just about the face up appearance. This way you can get an idea of what each eye will see. It requires practice, but it kinda makes a mockery of the idea that hand held vs stones in repeatable trays etc.
2. Round spread is not simply related to depth %. It is possible to have more than 10% variance in round weight with the same depth %. Princess can vary even more, but we believe all stones should be compared to a round diamond like a Tolkwosky standard.
3. Imagine Lance Armstrong might have taken 2 hours if it were not for the drugs (joke)

 

[Rhapsody]

From what I can understand the new round cut grading was supposed to help eliminate the occurance of AGS0 rounds that were not top performers in the old cut system. Does the new grading for princesses have the same pitfalls of having ranges where certain combinations work well and some do not or has AGS tried to work around that in the fancy grading as well?


And a question about the brilliancescope, its obviously possible to have a wonderful stone appear not so good has any one seen a stone the considered to have a bad cut score well on the BS?



And since this is my first post I probably should throw in a hello and say I appreciate the time and energy every one here has put into furthering knowledge

Ali

 

[pricescope]

Rhapsody, welcome to the forum.

 

[strmrdr]

Rhapsody welcome to PS.
You question is a good one and one that hasnt been fully answered yet.
The new cut grading is too new and not enough examples have been cut to give a definate answer yet in my opinion.
Paul having cut ags0 princess diamonds may be in the best postion to answer that.
He has also likely seen more of them than anyone outside of AGS.

 

[Garry H (Cut Nut)]

Date: 9/23/2005 8:03:59 PM
Author: Rhapsody Welcome; great questions!
From what I can understand the new round cut grading was supposed to help eliminate the occurance of AGS0 rounds that were not top performers in the old cut system. Does the new grading for princesses have the same pitfalls of having ranges where certain combinations work well and some do not or has AGS tried to work around that in the fancy grading as well? AGS''s new grades are based on computer ray tracing, not proportions. The proportions are only to help cutters know what proportions are likely to perform well. However the grading was established using ASET, and there will be variations - Sooper Dooper Ideal, Fab Ideal, VG ideal, Great Ideal, and hair of chinny chin chin ideal.


And a question about the brilliancescope, its obviously possible to have a wonderful stone appear not so good has any one seen a stone the considered to have a bad cut score well on the BS? Rhino, do you want to tell us all? (I am not sure I would if I were you) But i can say that there are diamonds we would all agree were bad, but they can score exceptionally well on the Bscope. This underlies the arguement that sergey has proposed that in establishing any cut grading system the master stone selection and test / comparison process is critical. It is human nature to design these systems to prove that regular well known good cuts score well. It is not human nature to design systems to show that bad stones are bad. The marketing people think that is crazy.



And since this is my first post I probably should throw in a hello and say I appreciate the time and energy every one here has put into furthering knowledge

Ali

 

[Rhino]

Date: 9/23/2005 8:03:59 PM
Author: Rhapsody
From what I can understand the new round cut grading was supposed to help eliminate the occurance of AGS0 rounds that were not top performers in the old cut system. Does the new grading for princesses have the same pitfalls of having ranges where certain combinations work well and some do not or has AGS tried to work around that in the fancy grading as well?


And a question about the brilliancescope, its obviously possible to have a wonderful stone appear not so good has any one seen a stone the considered to have a bad cut score well on the BS?


Ali

Before I hit the hay....

Dammit ... Pricescope is fricken addictive but our new friend raises an excellent question!

Ali... you are a keen student and this is a great question becuase 2 of the images I posted on this thread relate to and answer your question. The Gem Advisor images I posted that Garry cropped just a bit ago will help in demonstrating that the answer to your question is a resounding YES but with a clause which we will get to.

LOL... what a time for these questions eh Garry? When I'm up at work tomorow and if I can escape between appointments i'd like to demonstrate if time allows. If not it'll have to be over the weekend sometime. There are new insights I have gained with BrillianceScope that ya'll may find interesting which I discovered using Helium.

Peace,

 

[Garry H (Cut Nut)]

If you open this Gem Adviser attachemnt you will see that it has a very good Ideal-scope and ASET appearance (you can find the ASET view under the "light bulb" drop down >Options).

But it''s apearance in the ''office lighting'' supplied with the file shows it is not a great looking stone.

Yhe point to this is there is no one simple solution to designing cuts and cut grading systems. At first we thought colored reflectors would be good for these purposes - and do not get me wrong - they do help. But we need to be very careful.

Similar limitations apply to other direct assessment techniques (even though their inventors will claim otherwise).

 

[Rhino]

Date: 9/25/2005 5:32:55 AM
Author: Garry H (Cut Nut)
If you open this Gem Adviser attachemnt you will see that it has a very good Ideal-scope and ASET appearance (you can find the ASET view under the ''light bulb'' drop down >Options).

But it''s apearance in the ''office lighting'' supplied with the file shows it is not a great looking stone.

Yhe point to this is there is no one simple solution to designing cuts and cut grading systems. At first we thought colored reflectors would be good for these purposes - and do not get me wrong - they do help. But we need to be very careful.

Similar limitations apply to other direct assessment techniques (even though their inventors will claim otherwise).

Garry,

I would like your professional opinion about the 2 round stones I posted pictures of (the rounds). if you like I can send you Gem Advisor files, but on second thought I am going to perform anohter survey with the consumers based on those 2 stones to help answere ali''s question. My question is this.

There are opinions in the trade that would say *both* are bright stones. Each professional would have their reasons why, each of which I can understand and I am not agreeing or disagreeing about whose opinion would be correct.

My question to you is this.

Would it be fair to say that one diamond is bright at the expense of contrast, while one diamond is bright because of contrast?

I am about to post another poll based on these 2 stones. I am interested to see consumer input on this.

ali... once we round up some popular opinion I will proceed to answer your question.

 

[oldminer]

https://www.pricescope.com/community/threads/visualizing-roundness-and-table-percentage-issues.33981/

Hey guys, please take a look at this new thread. I have the diamond available for Rhino to measure with Helium if he''d like to scan it........It is only 0.28ct in weight, but the way it is cut and the way it measures may be of interest to many of you.

 

[mkb]

Hi,
I have been ''out of reach'' for a while, happy to be back.

I am currently cutting a few of the ''edge of AGS0'', just because I am curious what they will look like.
Table 55 Pavillion Angle 40.2 Crown angle 37 (?) in the 6mm range
Tanle 56 PA 40.2 CA 37.6
Doing this from 55 to 59% table.
I''m sure they''ll not be ''fish eye'', but they''ll be damn close.

Will keep you posted

br
luc

 

[Garry H (Cut Nut)]

Date: 9/27/2005 6:58:06 AM
Author: mkb
Hi,
I have been ''out of reach'' for a while, happy to be back.

I am currently cutting a few of the ''edge of AGS0'', just because I am curious what they will look like.
Table 55 Pavillion Angle 40.2 Crown angle 37 (?) in the 6mm range
Tanle 56 PA 40.2 CA 37.6
Doing this from 55 to 59% table.
I''m sure they''ll not be ''fish eye'', but they''ll be damn close.

Will keep you posted

br
luc

With a 40.2 pavilion I would keep the table below 57.5% Luc. I think the crown angle might be near or past their limit?

 

[mkb]

style="WIDTH: 99%; HEIGHT: 141px">Date: 9/27/2005 8:28:31 AM
Author: Garry H (Cut Nut)

Date: 9/27/2005 6:58:06 AM
Author: mkb
Hi,
I have been ''out of reach'' for a while, happy to be back.

I am currently cutting a few of the ''edge of AGS0'', just because I am curious what they will look like.
Table 55 Pavillion Angle 40.2 Crown angle 37 (?) in the 6mm range
Tanle 56 PA 40.2 CA 37.6
Doing this from 55 to 59% table.
I''m sure they''ll not be ''fish eye'', but they''ll be damn close.

Will keep you posted

br
luc

With a 40.2 pavilion I would keep the table below 57.5% Luc. I think the crown angle might be near or past their limit?

I agree Garry,
But I''m just following the AGS guideline (the extreme end for a O), because I find it hard to believe that that is still ''pretty''.
I''m not going too expensive on this test, using J SI2.

 

[Rhino]

Hi mkb,

If you like I can perform observation testing with it here in our store and see how consumer response is to it. I would only need it for roughly a week. I am keenly interested to see the results. Garry''s excellent advice has been if you want to learn more about diamonds, go to those with which you do not commonly deal with. I''ve been avoiding certain types of diamonds for a long time (ie. the type you mention) and with my studies on the new systems and how they correllate (differences/similarites) it is taking me down paths I never thought I''d be on. We have always generally avoided the extremes but with these new ideals (as in the case of this thread princess cuts) I was faced with a serious financial dilemma. Do I purchase a diamond, over 10k with Bscope results of low/medium/low and recommend this with a clear conscious? This has not been my typical modus operandi for a number of years. I can tell you now with full confidence that I am purchasing it and have done so! Many crossroads are happening for me in my life right now but if you would like my professional opinion coupled with the responses of John Q. Public and their opinions I will be happy to oblige. If not, no sweat.

Kind regards,

 

[mkb]

Hi Rhino,
thanks for the offer, I would love to see the results, I am currently in Bombai though, there would be a few logistic problems. I have acces to most of the equipment I need, I will be in touch.
If you would like to try different proportions on round or fancy, let me know I ''ll be happy to cut them (on our own goods). Our company is happy to research.

br
Luc

 

[JohnQuixote]

Date: 9/27/2005 9:33:34 AM
Author: Rhino
Hi mkb,

Many crossroads are happening for me in my life right now but if you would like my professional opinion coupled with the responses of John Q. Public and their opinions I will be happy to oblige. If not, no sweat.

Kind regards,

Huh? Wha? Who??

Oh... Nevermind.

 

[mkb]

I finished the test stones, and must say they don''t look half bad.
AGSO. No light leakage.
Beats me!

Luc

 

[Rhino]

Date: 9/28/2005 8:06:52 AM
Author: mkb
I finished the test stones, and must say they don't look half bad.
AGSO. No light leakage.
Beats me!

Luc

Sounds good mkb! If you would like to participate on a more active level in some of the research we are conducting in our lab/store it would be my pleasure to give you all kudo's when we publish the results which I will be pursuing with certain trade publications whom I have worked with in the past. For personal/professional reasons I am not publishing any of my current research on this forum. Contact me in pm and check off "email" and we can discuss further. We are finding differing results on certain AGS "0"'s which I believe you may find quite fascinating. No light leakage doesn't always mean what we think it may mean. Please send to my email as I will probably not be able to come on here perhaps till tomorrow morning.

Kind regards,
Jonathan

John Q. Public... a term I have come to use over the years referencing the consumer.