the more things change... 1953 ideal cut

[strmrdr]

This was baried on page 10 of another thread so I thought id put it in a new thread.

Thanks GIA for releasing the pdf files!
Thanks Serg for pointing out the article!

Procedures for Cutting and Grading of Diamonds by George R. Kaplan G&G Winter 1953-1954

http://lgdl.gia.edu/pdfs/gemsandgemology/freebackissues/winter_1953.pdf

This is a small quote from the article.

 

[strmrdr]

Here is a simulted IS image using the numbers in the article.
Other than the large culet it would be something you might see today as a top cut.
The lgf% is a little lower than I prefere but for the lighting of the time it was likely perfect.

 

[strmrdr]

Modern version

 

[Lynn B]

Interesting, thanks.

I see you got your old avatar back. Missed it, did ya''?!

 

[Lorelei]

Date: 1/29/2006 4:02:03 PM
Author: Lynn B
Interesting, thanks.

I see you got your old avatar back. Missed it, did ya''?!

Good catch Lynn - or are you going to alternate them Strm

 

[strmrdr]

Date: 1/29/2006 4:02:03 PM
Author: Lynn B
Interesting, thanks.


I see you got your old avatar back. Missed it, did ya'?!

O.T.
Yea I did :}

edit:
Lorelei:
I think I will stick with this one for a while people are used to it and it fits :}

 

[Kaleigh]

Date: 1/29/2006 4:37:40 PM
Author: strmrdr

Date: 1/29/2006 4:02:03 PM
Author: Lynn B
Interesting, thanks.


I see you got your old avatar back. Missed it, did ya''?!

O.T.
Yea I did :}

edit:
Lorelei:
I think I will stick with this one for a while people are used to it and it fits :}

Cool, I suits you, better than the other one.

 

[JohnQuixote]

Cool (original content - avatar is nice too).

 

[MissGotRocks]

Seems like the more things change the more they stay the same. Very interesting.

 

[valeria101]

Wait a minute... what stayed the same?

53% table is no longer top choice, open culet a no-go and the latest trend seems to favor LGF over 80% not below 70% like that. Other than this, the angles depend on physical properties that could hardly change... this leaving hair splitting aside.
What seems to have changed substantially is setting 'ideal cut' targets as a range than a fix target around which approximations are allowed. How much more precision and detail grew on the topic is anyone's guess - the difference seems quite overwhelming in that regard.
What am I missing?

 

[strmrdr]

Date: 1/29/2006 9:13:47 PM
Author: valeria101


Wait a minute... what stayed the same?


53% table is no longer top choice, open culet a no-go and the latest trend seems to favor LGF over 80% not below 70% like that. Other than this, the angles depend on physical properties that could hardly change... this leaving hair splitting aside.

What seems to have changed substantially is setting 'ideal cut' targets as a range than a fix target around which approximations are allowed. How much more precision and detail grew on the topic is anyone's guess - the difference seems quite overwhelming in that regard.

What am I missing?

53 table 34c 41p is a ags0 and a GIA EX.
There are a lot of diamonds cut with 75% LGF, 8* and simular diamonds.

 

[Paul-Antwerp]

I do think that you have to put this info into perspective.

In 1953, measuring up to 0.1 degrees, like we can today, was impossible. I am not even sure whether half a degree was discernable with the techniques of that time.

In the same way, the equipment did not allow cutting up to that same level.

Therefore, I think it is useless to deduct Diamcalc-files from this information. It seemed very precise at that time, it is not anymore.

Live long,

 

[Serg]

Date: 1/30/2006 10:07:03 AM
Author: Paul-Antwerp
I do think that you have to put this info into perspective.

In 1953, measuring up to 0.1 degrees, like we can today, was impossible. I am not even sure whether half a degree was discernable with the techniques of that time.

In the same way, the equipment did not allow cutting up to that same level.

Therefore, I think it is useless to deduct Diamcalc-files from this information. It seemed very precise at that time, it is not anymore.

Live long,

re:measuring up to 0.1 degrees, like we can today, was impossible

Paul,

It was possible. It was less user friendly, but is was possible.
Btw, I read old G&G each evening now, Wonderful. Much more interesting and helpful for me than modern G&G

 

[valeria101]

Date: 1/29/2006 9:30:42 PM
Author: strmrdr

53 table 34c 41p is a ags0 and a GIA EX.

Right. Even with a whole lot of stats at hand, and I still missed the obvious... that there are lots and lots of diamonds on all walks of cut with small tables like this. What make me think that larger than the AGS0 range allows is more often found than smaller (or at least towards the low end) ? Strange enough.

Thanks!