a cut question. to garry h and others

[gbreaux]

could you look and see if this round has any warning signs or red flags please: i have it on hold and am ready to purchase

http://www.goodoldgold.com/diamond/3496/

until i found this one, i was looking hard at this H / VS2: http://www.goodoldgold.com/diamond/3501/

the only thing i don''t have on the diamonds are the pavillion angle spreads. this is on the sarin report i believe.

based on the other specs, should i be concerned to not have the pavillion spread. the fire/brillance on the G / VS1 looks to be great on the charts.

does the G / VS1 look to be worthy of the price??????? this is what i''m wondering.

thanks for the help.

 

[strmrdr]

I like the cut of the first one slighly better but there isnt a whole lot of difference.
Both should rock your world :}
The pavilion angle spread is in the pdf file under the helium scan tab.

 

[strmrdr]

Orange is the spread:
H/vs2 - reasonably tight
Diameter, mm 6.458 6.450 6.467 0.27% N/A EX Good Old Gold, Inc.
Crown angle, ° 34.95 34.77 35.08 0.31
Pavilion angle, ° 40.83 40.65 41.03 0.38

g/vs1 - super tight.
Crown angle, ° 34.35 34.24 34.48 0.23
Pavilion angle, ° 40.76 40.66 40.81 0.15

Considering that with some well known super-ideal branded stones 1 degree crown and .5 pavilion isnt uncommom both are fine as far as tightness goes.

 

[gbreaux]

thanks for the help on the spread. i didn''t know that. i called jon @ gog and he found and read them to me and the g vs1 was super tight...but now i know how to find them myself.

the first one is g vs1, but you''re right, i don''t think there is that much difference between the two. it looks like a good h vs2 as well. the price is much better on the h for sure, but i''m going to stretch and get the g color.

thanks for looking and commenting.

 

[Garry H (Cut Nut)]

This vendor will give you honest advice and can compare the stones and talk you through it. I do not have the stones - so can not help you anywhere near as much.

Date: 10/11/2007 9:29:23 PM
Author: strmrdr
Orange is the spread:
H/vs2 - reasonably tight
Diameter, mm 6.458 6.450 6.467 0.27% N/A EX Good Old Gold, Inc.
Crown angle, ° 34.95 34.77 35.08 0.31
Pavilion angle, ° 40.83 40.65 41.03 0.38

g/vs1 - super tight.
Crown angle, ° 34.35 34.24 34.48 0.23
Pavilion angle, ° 40.76 40.66 40.81 0.15

Considering that with some well known super-ideal branded stones 1 degree crown and .5 pavilion isnt uncommom both are fine as far as tightness goes.

Storm surely you can see this first stone has no crown or pavilion angle deviation. It has a very slight 0.15ish degree of table tilt which does nothing to the optics, and doubles the variance in the C and P based on the simplistic scan data.

If you go to http://www.goodoldgold.com/items/3496/illustrated%20report.pdf and read the report thoroughly you can see there is actually only 0.12 and 0.11 degrees of crown and pavilion variation.

Your better understanding of this will improve the quality of your generally sound advice.

 

[strmrdr]

Date: 10/11/2007 9:47:17 PM
Author: Garry H (Cut Nut)
This vendor will give you honest advice and can compare the stones and talk you through it. I do not have the stones - so can not help you anywhere near as much.


Storm surely you can see this first stone has no crown or pavilion angle deviation. It has a very slight 0.15ish degree of table tilt which does nothing to the optics, and doubles the variance in the C and P based on the simplistic scan data.

If you go to http://www.goodoldgold.com/items/3496/illustrated%20report.pdf and read the report thoroughly you can see there is actually only 0.12 and 0.11 degrees of crown and pavilion variation.

Your better understanding of this will improve the quality of your generally sound advice.

Yep but which is a better measure of workmanship?
Absolute tightness or relative to the table.
Since all measurements are taken relative too the table it is the number I prefer.
Its a better measurement of overall workmanship.
When the spreads are larger than either of these then I might make the distinction but honestly neither of these stones need any excuses.
Either way you look at it its one tight puppy :}

 

[Garry H (Cut Nut)]

Date: 10/11/2007 10:24:29 PM
Author: strmrdr
Yep but which is a better measure of workmanship? this is exactly what I am talking about - it is very likely that the tiniest piece of dust is sitting on the scanner table and the stone is slightly tilted - you shoot stones down sometimes without taking this factor into account.

Absolute tightness or relative to the table.
Since all measurements are taken relative too the table it is the number I prefer. Again as i have mentioned before, because the industry uses this basis does not mean it is valid. It is an invalid method of measurement - a more valid method for nerds like us who are interested in a diamonds optical performance is to use the average of an axis through the pavilion because that is the driver of light peformance.

Even if there is a workmanship issue because the table is not parrallel with the girdle, or the pavilion axis is not perpendicular to the table, it is clear that light entering the table that has a 1 degree titl (= 2 degrees of crown and 2 degrees of pavilion angle deviation across the stone) will only deviate by about 0.2 or 0.3 degrees. So the validity of any penalty that you should impose for such a traversty is greatly rduced.

Its a better measurement of overall workmanship. In this case we should be using Bill Brae''s system and not bothering to look at the diamond Storm?
When the spreads are larger than either of these then I might make the distinction but honestly neither of these stones need any excuses.
Either way you look at it its one tight puppy :} I have agreed that there is nothing wrong with this stone Storm, even less than you indicated

 

[gbreaux]

Thanks guys. I put a deposit on the G / VS1 a soon as I saw it and that''s the one I''m getting.


I''m going to have to get my wife one of those t-shirts that says, " Call 911 - cause I''m Cut".

ha ha

 

[Rhino]

Thanks for pointing this out Garry. My eyes tend to go first to the DEV column up top on the Helium Report and I totally overlooked the Octonus Theory towards the bottom. Just a question. Is there a thread wherein you comment more on the Bray system? I''m curious to know your opinion on that. That is one online technology I haven''t researched much but was curious to know if any independant opinions have been published on the subject. If so can you link me? If not, care to share your thoughts?

Kind regards,

 

[stebbo]

Date: 10/12/2007 2:56:01 AM
Author: Garry H (Cut Nut)
it is very likely that the tiniest piece of dust is sitting on the scanner table and the stone is slightly tilted

Maybe the scanner boys should be looking into averaging multiple scans of the same diamond cleaned and placed at different orientations (similar to ICE technology on film scanners). Improvement in accuracy all round and minimization of error due to dust.

It is an invalid method of measurement - a more valid method for nerds like us who are interested in a diamonds optical performance is to use the average of an axis through the pavilion because that is the driver of light peformance.

Not sure what you mean by 'average of an axis through the pavilion' (an average of a single thing?). A single axis would be great, but so incredibly hard to define. Octonus somehow define a girdle center point but even they still effectively use 4 pavilion and 4 crown axes in their theory.

 

[Garry H (Cut Nut)]

Date: 10/12/2007 11:56:47 AM
Author: Rhino
Thanks for pointing this out Garry. My eyes tend to go first to the DEV column up top on the Helium Report and I totally overlooked the Octonus Theory towards the bottom. Just a question. Is there a thread wherein you comment more on the Bray system? I''m curious to know your opinion on that. That is one online technology I haven''t researched much but was curious to know if any independant opinions have been published on the subject. If so can you link me? If not, care to share your thoughts?

Kind regards,

Rhino and Stebbo, this OctoNus theory has been discussed many times here. I have linked to this article we wrote about it some years back. I usually link to this page in the article http://www.gemology.ru/cut/english/symmetry/6.htm but you should read it all if you wish to have a full understanding.

Bill Brae''s system measures the outside of the stone. In numerous discussions here on Pricescope he has said he is not that interested in optical performance symmetry. but do not take my word for it please.... I just tried to find his Pscope name - perhaps i am mispelling it? Help?

 

[JohnQuixote]

Date: 10/12/2007 10:54:37 PM
Author: Garry H (Cut Nut)

Bill Brae''s system measures the outside of the stone. In numerous discussions here on Pricescope he has said he is not that interested in optical performance symmetry. but do not take my word for it please.... I just tried to find his Pscope name - perhaps i am mispelling it? Help?

Bill Bray: http://www.brayscore.com/

Pricescope name: He Scores

 

[Garry H (Cut Nut)]

thx John
https://www.pricescope.com/idealbb/profile/myprofile.asp?userID=12650 here he is - you can find all his posts here for Bill Bray with a Y

BTW it must be very relaxing there without Brian the Cutter slashing everyone. He was here in my office making me answer difficult questions last week - actually we had a great discussion about the past, present and mostly the future. But I think he wants to move here, so maybe he can buy me out?

 

[stebbo]

Date: 10/12/2007 10:54:37 PM
Author: Garry H (Cut Nut)
Rhino and Stebbo, this OctoNus theory has been discussed many times here. I have linked to this article we wrote about it some years back. I usually link to this page in the article http://www.gemology.ru/cut/english/symmetry/6.htm but you should read it all if you wish to have a full understanding.

My comment was based on a full understanding of that article--it made total sense. Is there something I mis-interpreted?

Bill's pscope name was something like "He Scores" from memory wasn't it? (Bill must be good with the ladies)

 

[Garry H (Cut Nut)]

Date: 10/12/2007 10:16:55 PM
Author: stebbo

Date: 10/12/2007 2:56:01 AM
Author: Garry H (Cut Nut)
it is very likely that the tiniest piece of dust is sitting on the scanner table and the stone is slightly tilted

Maybe the scanner boys should be looking into averaging multiple scans of the same diamond cleaned and placed at different orientations (similar to ICE technology on film scanners). Improvement in accuracy all round and minimization of error due to dust.

It is an invalid method of measurement - a more valid method for nerds like us who are interested in a diamonds optical performance is to use the average of an axis through the pavilion because that is the driver of light peformance.

Not sure what you mean by ''average of an axis through the pavilion'' (an average of a single thing?). A single axis would be great, but so incredibly hard to define. Octonus somehow define a girdle center point but even they still effectively use 4 pavilion and 4 crown axes in their theory.

sorry Stebbo.
Yes - a weighted average axis would be the best we could get - about 10 times weighting to mean of 8 pavilion mains axis, 2 times for mean of crown mains and 1 times table woud be more or less a fair estimate.

That is about the appropriate weighting and why I rarely get upset when i see a crown and pavilion deviation that are in the same value range - 90% of such stones have a tilted table.

Then when I see an ideal-scope image, or the stone has H&A''s - it is a nobrainer to worry about this nonsensical numeric deviation.

 

[stebbo]

Date: 10/12/2007 11:54:22 PM
Author: Garry H (Cut Nut)

sorry Stebbo.

Yes - a weighted average axis would be the best we could get - about 10 times weighting to mean of 8 pavilion mains axis, 2 times for mean of crown mains and 1 times table woud be more or less a fair estimate.

That is about the appropriate weighting and why I rarely get upset when i see a crown and pavilion deviation that are in the same value range - 90% of such stones have a tilted table.

Then when I see an ideal-scope image, or the stone has H&A's - it is a nobrainer to worry about this nonsensical numeric deviation.

100% agree there. Even this matching of opposites that gets mentioned every now and again, it's only a small fraction of incident light that bounces across to its opposite facet--I can't understand the fuss.

I'd love to see the results of a "tightness versus optical symmetry" experiment.

 

[gbreaux]

tightness vs. optical symmetry... now that is something I understand, (I think). I am enjoying reading all the other stuff though.

In my quest to find the best diamond for my sweet, I have been looking for the tightest cut 1 carat for my budget. It was my thinking from reading, mostly on this board, that this would give me the diamond that had most brillianinace and the most fire...and would stay that way forever.

If you do a search on my name, gbreaux, you''ll see that I found and came to this site while dealing w/ Diamond Cutters International. It seemed every diamond I found was either warped or a Class III or Class IV.

Well..what I found here confirmed my suspicions so I didn''t dwell on that long.

We had found a Verragio setting and I just needed to find the rock to put in it.

It was between an 1.03, H / VS2 and a 1.02, G / VS1. I finally decided on the G / VS1.

So...just for kicks, I wrote Dee @ DCI to let her know when I finalized my purchase and thank her for all her help! Here, I''ll cut and paste:


--------------------------------------------------------------------------------
Sent: Friday, October 12, 2007 2:02 PM
To: [email protected]
Subject: RE: Follow Up

Dee,

it''s done! heres the setting: verragio. look at the center picture it shows better. i wired the $$ for it an hour ago.

http://www.billbarnes.com/product.asp?product=7133

and here''s the rock. i place a down payment and will pay in full when the setting comes in.

http://www.goodoldgold.com/diamond/3496/

the setting is coming from verragio w/ F-G / VS side stones. should be a nice popping ring.

thanks for your help.

Gene,

I’m glad to you decided on a ring. I guess you don’t mind a class 4 stone in the end. There are advantages to these commercial grade stone. They are a lot more affordable. Congrats on finishing your search.

Sincerely,

Dee

And then, immediately after, she sent another, unsolicited response:



Gene,
If you don’t mind the low light return, that stone should be around $6221. If they sell it for more than that, let me know. I can get it for you. Save the money.

Unbelievable; I just thought you guys might want to see more info on how these scoundrels operate!!


BTW, I am very confident that Jon and Marie of Good Old Gold, will give us an honest, square deal on the nicest rock we have ever seen and I have the people on this board to thank for that.

Thank everyone who responded to my questions. Your answers are what help us all.

 

[WorkingHardforSmallRewards]

I think she forgot to look at the key on her chart. It must be 1-4 Four being the best.

If not...email her and ask her for cut criteria or an example for a Class 1 cut and see what she produces

 

[whatmeworry]

Date: 10/13/2007 11:51:53 AM
Author: gbreaux

tightness vs. optical symmetry... now that is something I understand, (I think). I am enjoying reading all the other stuff though.

In my quest to find the best diamond for my sweet, I have been looking for the tightest cut 1 carat for my budget. It was my thinking from reading, mostly on this board, that this would give me the diamond that had most brillianinace and the most fire...and would stay that way forever.

If you do a search on my name, gbreaux, you''ll see that I found and came to this site while dealing w/ Diamond Cutters International. It seemed every diamond I found was either warped or a Class III or Class IV.

Well..what I found here confirmed my suspicions so I didn''t dwell on that long.

We had found a Verragio setting and I just needed to find the rock to put in it.

It was between an 1.03, H / VS2 and a 1.02, G / VS1. I finally decided on the G / VS1.

So...just for kicks, I wrote Dee @ DCI to let her know when I finalized my purchase and thank her for all her help! Here, I''ll cut and paste:


--------------------------------------------------------------------------------

Sent: Friday, October 12, 2007 2:02 PM
To: [email protected]
Subject: RE: Follow Up

Dee,

it''s done! heres the setting: verragio. look at the center picture it shows better. i wired the $$ for it an hour ago.

http://www.billbarnes.com/product.asp?product=7133

and here''s the rock. i place a down payment and will pay in full when the setting comes in.

http://www.goodoldgold.com/diamond/3496/

the setting is coming from verragio w/ F-G / VS side stones. should be a nice popping ring.

thanks for your help.

Gene,

I’m glad to you decided on a ring. I guess you don’t mind a class 4 stone in the end. There are advantages to these commercial grade stone. They are a lot more affordable. Congrats on finishing your search.

Sincerely,

Dee

And then, immediately after, she sent another, unsolicited response:



Gene,

If you don’t mind the low light return, that stone should be around $6221. If they sell it for more than that, let me know. I can get it for you. Save the money.

Unbelievable; I just thought you guys might want to see more info on how these scoundrels operate!!


BTW, I am very confident that Jon and Marie of Good Old Gold, will give us an honest, square deal on the nicest rock we have ever seen and I have the people on this board to thank for that.

Thank everyone who responded to my questions. Your answers are what help us all.

Congratulations on going with a low light return, Class IV stone.

. Heh, heh. I''d be curious as to how they could get a GOG in-house stone and sell it to you cheaper than GOG!

 

[stebbo]

Date: 10/13/2007 11:51:53 AM
Author: gbreaux

...

and here''s the rock. i place a down payment and will pay in full when the setting comes in.

http://www.goodoldgold.com/diamond/3496/

...

Gene,

I’m glad to you decided on a ring. I guess you don’t mind a class 4 stone in the end. There are advantages to these commercial grade stone. They are a lot more affordable. Congrats on finishing your search.

Sellling commercial grade now Jon?

 

[strmrdr]

Date: 10/13/2007 11:51:53 AM
Author: gbreaux

So...just for kicks, I wrote Dee @ DCI to let her know when I finalized my purchase and thank her for all her help! Here, I''ll cut and paste:


--------------------------------------------------------------------------------

Sent: Friday, October 12, 2007 2:02 PM
To: [email protected]
Subject: RE: Follow Up

Dee,

it''s done! heres the setting: verragio. look at the center picture it shows better. i wired the $$ for it an hour ago.

http://www.billbarnes.com/product.asp?product=7133

and here''s the rock. i place a down payment and will pay in full when the setting comes in.

http://www.goodoldgold.com/diamond/3496/

the setting is coming from verragio w/ F-G / VS side stones. should be a nice popping ring.

thanks for your help.

Gene,

I’m glad to you decided on a ring. I guess you don’t mind a class 4 stone in the end. There are advantages to these commercial grade stone. They are a lot more affordable. Congrats on finishing your search.

Sincerely,

Dee

And then, immediately after, she sent another, unsolicited response:



Gene,

If you don’t mind the low light return, that stone should be around $6221. If they sell it for more than that, let me know. I can get it for you. Save the money.

Unbelievable; I just thought you guys might want to see more info on how these scoundrels operate!!


BTW, I am very confident that Jon and Marie of Good Old Gold, will give us an honest, square deal on the nicest rock we have ever seen and I have the people on this board to thank for that.

Thank everyone who responded to my questions. Your answers are what help us all.

That would be funny if it wasnt so sick.
Who do those people think they are? sheesh
Not that my opinion of dci could get any lower but it just did.....

 

[strmrdr]

Date: 10/12/2007 2:56:01 AM
Author: Garry H (Cut Nut)

Date: 10/11/2007 10:24:29 PM
Author: strmrdr
Yep but which is a better measure of workmanship? this is exactly what I am talking about - it is very likely that the tiniest piece of dust is sitting on the scanner table and the stone is slightly tilted - you shoot stones down sometimes without taking this factor into account.

Absolute tightness or relative to the table.
Since all measurements are taken relative too the table it is the number I prefer. Again as i have mentioned before, because the industry uses this basis does not mean it is valid. It is an invalid method of measurement - a more valid method for nerds like us who are interested in a diamonds optical performance is to use the average of an axis through the pavilion because that is the driver of light peformance.

Even if there is a workmanship issue because the table is not parrallel with the girdle, or the pavilion axis is not perpendicular to the table, it is clear that light entering the table that has a 1 degree titl (= 2 degrees of crown and 2 degrees of pavilion angle deviation across the stone) will only deviate by about 0.2 or 0.3 degrees. So the validity of any penalty that you should impose for such a traversty is greatly rduced.

Its a better measurement of overall workmanship. In this case we should be using Bill Brae''s system and not bothering to look at the diamond Storm?
When the spreads are larger than either of these then I might make the distinction but honestly neither of these stones need any excuses.
Either way you look at it its one tight puppy :} I have agreed that there is nothing wrong with this stone Storm, even less than you indicated

I don''t think we are going to agree on this,,,
To some a certain color or clarity grade is a mind clean thing.
My mind clean is workmanship, hearts and tightness of the angles on rounds.
Patterns on step cuts.
I see the whole table tilt issue as making excuses.

 

[Garry H (Cut Nut)]

Date: 10/13/2007 9:50:04 PM
Author: strmrdr

Date: 10/12/2007 2:56:01 AM
Author: Garry H (Cut Nut)

Date: 10/11/2007 10:24:29 PM
Author: strmrdr
Yep but which is a better measure of workmanship? this is exactly what I am talking about - it is very likely that the tiniest piece of dust is sitting on the scanner table and the stone is slightly tilted - you shoot stones down sometimes without taking this factor into account.

Absolute tightness or relative to the table.
Since all measurements are taken relative too the table it is the number I prefer. Again as i have mentioned before, because the industry uses this basis does not mean it is valid. It is an invalid method of measurement - a more valid method for nerds like us who are interested in a diamonds optical performance is to use the average of an axis through the pavilion because that is the driver of light peformance.

Even if there is a workmanship issue because the table is not parrallel with the girdle, or the pavilion axis is not perpendicular to the table, it is clear that light entering the table that has a 1 degree titl (= 2 degrees of crown and 2 degrees of pavilion angle deviation across the stone) will only deviate by about 0.2 or 0.3 degrees. So the validity of any penalty that you should impose for such a traversty is greatly rduced.

Its a better measurement of overall workmanship. In this case we should be using Bill Brae''s system and not bothering to look at the diamond Storm?
When the spreads are larger than either of these then I might make the distinction but honestly neither of these stones need any excuses.
Either way you look at it its one tight puppy :} I have agreed that there is nothing wrong with this stone Storm, even less than you indicated

I don''t think we are going to agree on this,,,
To some a certain color or clarity grade is a mind clean thing.
My mind clean is workmanship, hearts and tightness of the angles on rounds.
Patterns on step cuts.
I see the whole table tilt issue as making excuses.

Storm we either have a knowledge, philiosophy or some other point of difference.

from my side data and reality should match. When the data has a variance and the nature of stuff does not reflect that variance, then the data is useless.

If you like data for the sake of data, then fine.

But I think that it is fair that you warn people that this is your philiosophy when advising people about their selction of diamonds.

 

[strmrdr]

Date: 10/14/2007 8:34:44 PM
Author: Garry H (Cut Nut)
Storm we either have a knowledge, philiosophy or some other point of difference.

from my side data and reality should match. When the data has a variance and the nature of stuff does not reflect that variance, then the data is useless.

If you like data for the sake of data, then fine.

But I think that it is fair that you warn people that this is your philiosophy when advising people about their selction of diamonds.

Hey Garry, its been a long day so I''m going to keep it short.
The data does reflect workmanship, good, bad or ugly.


I rarely shoot stones down for angle variance unless it gets pretty extreme.
The stones cut each year that meet my highest standards likely wouldn''t even fill a small hat and is way too limiting at this time within the current market.
The angles need to cut right way more often first before we can move on too near perfect hearts then too near perfect tightness in the overall market.
The PS market is a lot different because we have a group of dedicated vendors that feed our insanity with near perfect hearts and generally vg or better tightness.

I admire great workmanship and the skill of those that craft it.
When a stone comes along that meets it with no excuses I''m going to comment on it. :}

 

[Rhino]

Thanks for the links guys.

Date: 10/13/2007 7:41:31 PM
Author: stebbo

Sellling commercial grade now Jon?

Yea stebbo, I really got a kick out of this. Gene was kind enough to share their most insightful commentary with me.

 

[Garry H (Cut Nut)]

Sorry Storm, you have indeed mislead in this case. The comments you made would indicate that the tightest stone is the least tight stone - see my values for the OctoNus approach in blue beside yours in orange

Date: 10/11/2007 9:29:23 PM
Author: strmrdr
Orange is the spread:
H/vs2 - reasonably tight
Diameter, mm 6.458 6.450 6.467 0.27% N/A EX Good Old Gold, Inc.
Crown angle, ° 34.95 34.77 35.08 0.31 0.13
Pavilion angle, ° 40.83 40.65 41.03 0.38 0.07

g/vs1 - super tight.
Crown angle, ° 34.35 34.24 34.48 0.23 0.12
Pavilion angle, ° 40.76 40.66 40.81 0.15 0.10

Considering that with some well known super-ideal branded stones 1 degree crown and .5 pavilion isnt uncommom both are fine as far as tightness goes.

So infact the stone you indicated as being reasnoably tight is optically the tighter, and the "super tight" stone is ever so slightly less tight.

Now what you are claiming to be cutter error is justor more likely to be scanner operator error when the deviation in Crown = the deviation in pavilion. (I am not suggesting in this case because Jon is I am sure a stickler for cleanliness). A tiny piece of dust can float out of the air after the operator has given the table a blast of compressed air or a wipe with a cloth.

 

[strmrdr]

Date: 10/15/2007 1:05:29 AM
Author: Garry H (Cut Nut)
Sorry Storm, you have indeed mislead in this case. The comments you made would indicate that the tightest stone is the least tight stone - see my values for the OctoNus approach in blue beside yours in orange

Date: 10/11/2007 9:29:23 PM
Author: strmrdr
Orange is the spread:
H/vs2 - reasonably tight
Diameter, mm 6.458 6.450 6.467 0.27% N/A EX Good Old Gold, Inc.
Crown angle, ° 34.95 34.77 35.08 0.31 0.13
Pavilion angle, ° 40.83 40.65 41.03 0.38 0.07

g/vs1 - super tight.
Crown angle, ° 34.35 34.24 34.48 0.23 0.12
Pavilion angle, ° 40.76 40.66 40.81 0.15 0.10

Considering that with some well known super-ideal branded stones 1 degree crown and .5 pavilion isnt uncommom both are fine as far as tightness goes.

So infact the stone you indicated as being reasnoably tight is optically the tighter, and the ''super tight'' stone is ever so slightly less tight.

Now what you are claiming to be cutter error is justor more likely to be scanner operator error when the deviation in Crown = the deviation in pavilion. (I am not suggesting in this case because Jon is I am sure a stickler for cleanliness). A tiny piece of dust can float out of the air after the operator has given the table a blast of compressed air or a wipe with a cloth.

Lack of table tilt is a part of being tight. bottom line :}
Its the largest facet it should be lined up properly dontcha think?

 

[WorkingHardforSmallRewards]

Date: 10/15/2007 1:05:29 AM
Author: Garry H (Cut Nut)
Sorry Storm, you have indeed mislead in this case. The comments you made would indicate that the tightest stone is the least tight stone - see my values for the OctoNus approach in blue beside yours in orange

Date: 10/11/2007 9:29:23 PM

Author: strmrdr

Orange is the spread:

H/vs2 - reasonably tight

Diameter, mm 6.458 6.450 6.467 0.27% N/A EX Good Old Gold, Inc.

Crown angle, ° 34.95 34.77 35.08 0.31 0.13

Pavilion angle, ° 40.83 40.65 41.03 0.38 0.07


g/vs1 - super tight.

Crown angle, ° 34.35 34.24 34.48 0.23 0.12

Pavilion angle, ° 40.76 40.66 40.81 0.15 0.10


Considering that with some well known super-ideal branded stones 1 degree crown and .5 pavilion isnt uncommom both are fine as far as tightness goes.

So infact the stone you indicated as being reasnoably tight is optically the tighter, and the ''super tight'' stone is ever so slightly less tight.


Now what you are claiming to be cutter error is justor more likely to be scanner operator error when the deviation in Crown = the deviation in pavilion. (I am not suggesting in this case because Jon is I am sure a stickler for cleanliness). A tiny piece of dust can float out of the air after the operator has given the table a blast of compressed air or a wipe with a cloth.

what size dust particles are we talking about? I will tell you, I worked hard and long to keep my fiance''s ring clean, but whenever I brought out the loupe there was always something left to be blown off....

wouldnt it be just as easy for a little piece of dust or hair to have gotten on the diamond as it would be for it to have landed on that portion of the scanner? thus doubling the likely hood

or are those loupe pieces of dust too small to count

 

[WorkingHardforSmallRewards]

What are the most common reasons for table tilt anyway? and how common is it within various degrees?

(and don't lose sight of the most important part of this thread....somebody called GOG AGS0 Hearts and Arrows a low light returning class 4 diamond....)lol...

and narrowed down an appropriate price to the single dollars digit...which was not a 0 or 5 if I recall correctly...that was perhaps my favorite part. 6221 it was...that is quite an estimation of appropriate value over an email analysis...

 

[Garry H (Cut Nut)]

WH4SR there have been links off to technical discussions about this. They are a bit boring though.
Simply:

1. dust under the table on the scanner table - so deviations in the crown and the pavilion will match in a perfectly symmetrical stone. The deviations will be exactly 2X the tilt induced in the table by the dust.


2. dust or dirt under the table in the polishing dop


3. slippage in the dop during polishing

In the last 2 cases there is no basis for the deviation in the crown to match the deviation in the pavilion. That is why I could suspect that Storm was wrong in his initial recomendation.