Find your diamond
Find your jewelry
shape
carat
color
clarity

John''s "Cliff Notes"

Status
Not open for further replies. Please create a new topic or request for this thread to be opened.

Regular Guy

Ideal_Rock
Joined
Jul 6, 2004
Messages
5,954

Lorelei

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
42,064
Date: 3/4/2009 12:39:58 AM
Author: Regular Guy

Date: 3/3/2009 11:06:19 PM
Author:melanie987123
As referenced in the below thread regarding AGS/GIA overlap. Can''t find them via a search, can anyone help? Much appreciated!

https://www.pricescope.com/community/threads/very-good-2ct-vs-ideal-hearts-and-arrows-1-5-ct.108438/
Kind of an odd redaction here...John pointing to his own comment, being supported by Lorelei, and searching on Lorelei and cliff notes to find them.

But...there you go...
Thanks Ira!
 

John P

Ideal_Rock
Trade
Joined
May 1, 2008
Messages
3,563
Date: 3/3/2009 11:06:19 PM
Author:melanie987123

As referenced in the below thread regarding AGS/GIA overlap. Can''t find them via a search, can anyone help? Much appreciated!
Hi Melanie. I think they were included in that thread, but just in case here is the original iteration (circa 07).


*

Configurations depend on each other. A little give here can still work with a little take there.

With that said, here''s a "Cliff''s Notes" for staying near-Tolkowsky angles with GIA reports (their numbers are rounded): A crown angle of 34.0, 34.5 or 35.0 is usually safe with a 40.8 pavilion angle. If pavilion angle = 40.6 lean toward a 34.5-35.0 crown. If pavilion angle = 41 lean toward a 34.0-34.5 crown.

GIA "EX" in cut is great at its heart, but it ranges a bit wider than some people prefer, particularly in deep combinations (pavilion > 41 with crown > 35).

Of course all this is by the numbers and averages on a grading report don''t tell the whole story. Actual images like ideal-scope or ASET are needed if you''d like meaningful feedback about performance potential. Most importantly, we won''t have the chance to see the diamond. If you do be sure to view it in several lighting conditions - not just under spotlights.

*

While it''s easy to focus on the numbers above the most important part is really the italicized... While I''m keen on the HCA as a cursory rejection tool and I applaud the GIA, AGS and AGA systems for their strengths no system is perfect. So the above is really a guideline intended to keep your wheels on the road towards top performance in round brilliants. Much more information is needed to guide you to your chosen performance destination however.

There was a detailed discussion in this thread about the limitations of numbers. While I admit to being very analytic (ok ok OCD) I prefer to go through all the motions and precautions in PS threads as if I were buying for myself.
 

strmrdr

Super_Ideal_Rock
Joined
Nov 1, 2003
Messages
23,295
Point of order that has been bugging me for a long time...

Those notes are to find a diamond "near-Tolkowsky".
I think John would agree there are a lot of beautiful high performance diamonds that are not "near-Tolkowsky".
"near-Tolkowsky" is just one range of many a beautiful high performance diamond can fall into.
 

melz

Shiny_Rock
Joined
Feb 24, 2009
Messages
405
Storm your comment reminded me I came across a diamond the other day with a Tolkwosky certificate and wasn't sure what to make of it. Is it going to be a guaranteed performer? Better than say an AGS with otherwise equivalent specs or a GOG or WF branded diamond?
 

Lorelei

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
42,064
Date: 3/4/2009 7:43:11 AM
Author: melanie987123
Thanks for humoring me ... didn''t realize that was what the reference was to! What a great board. Not sure what I''m going to do with myself when I''m engaged and done shopping for diamonds .....
Then you start thinking about earrings or a pendant....
 

Ellen

Super_Ideal_Rock
Joined
Jan 13, 2006
Messages
24,427
Date: 3/4/2009 7:04:00 AM
Author: strmrdr
Point of order that has been bugging me for a long time...

Those notes are to find a diamond ''near-Tolkowsky''.
I think John would agree there are a lot of beautiful high performance diamonds that are not ''near-Tolkowsky''.
''near-Tolkowsky'' is just one range of many a beautiful high performance diamond can fall into.
True enough strm. But most coming on here are not looking for the "other" beauties (and those few who are, usually say so), so this just helps narrow down/ease the search process for newbs.To elaborate on, and list all the caveats to get other cuts that are worthwhile, would just add stress and confusion to the process. imho
 

John P

Ideal_Rock
Trade
Joined
May 1, 2008
Messages
3,563
Date: 3/4/2009 7:04:00 AM
Author: strmrdr
Point of order that has been bugging me for a long time...

Those notes are to find a diamond ''near-Tolkowsky''.
I think John would agree there are a lot of beautiful high performance diamonds that are not ''near-Tolkowsky''.
''near-Tolkowsky'' is just one range of many a beautiful high performance diamond can fall into.
Sure. It''s one of the reasons I specified near-Tolk angles ... and not just near-Tolk makes.

When you seek a round brilliant away from those angles, regardless of make, the give-take statement in the first sentence applies. At that point I think insistence on further data like IS and ASET becomes even more important.
 

Ellen

Super_Ideal_Rock
Joined
Jan 13, 2006
Messages
24,427
Date: 3/4/2009 8:00:46 AM
Author: John Pollard

Date: 3/4/2009 7:04:00 AM
Author: strmrdr
Point of order that has been bugging me for a long time...

Those notes are to find a diamond ''near-Tolkowsky''.
I think John would agree there are a lot of beautiful high performance diamonds that are not ''near-Tolkowsky''.
''near-Tolkowsky'' is just one range of many a beautiful high performance diamond can fall into.
Sure. It''s one of the reasons I specified near-Tolk angles ... and not just near-Tolk makes.

When you seek a round brilliant away from those angles, regardless of make, the give-take statement in the first sentence applies. At that point I think insistence on further data like IS and ASET becomes even more important.
Exactly. I started to come back to edit my post, as I hadn''t been specific on that.
 

John P

Ideal_Rock
Trade
Joined
May 1, 2008
Messages
3,563
Date: 3/4/2009 7:58:51 AM
Author: Ellen

True enough strm. But most coming on here are not looking for the 'other' beauties (and those few who are, usually say so), so this just helps narrow down/ease the search process for newbs.To elaborate on, and list all the caveats to get other cuts that are worthwhile, would just add stress and confusion to the process. imho
Indeed Ellen. That was the reason the "Cliff's Notes" surfaced. To stop parroting same-info over and over to newbs looking at dubious combos...getting them back onto a well agreed-upon road.

Karl is saying there are other scenic routes. It's true, but those roads are less certain and often require specific guidance. At that point there are regulars who generally surface to help guide & decide.
 

Lorelei

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
42,064
Date: 3/4/2009 8:10:01 AM
Author: John Pollard

Date: 3/4/2009 7:58:51 AM
Author: Ellen

True enough strm. But most coming on here are not looking for the ''other'' beauties (and those few who are, usually say so), so this just helps narrow down/ease the search process for newbs.To elaborate on, and list all the caveats to get other cuts that are worthwhile, would just add stress and confusion to the process. imho
Indeed Ellen. That was the reason the ''Cliff''s Notes'' surfaced. To stop parroting same-info over and over to newbs looking at dubious combos...getting them back onto a well agreed-upon road.

Karl is saying there are other scenic routes. It''s true, but those roads are less certain and often require specific guidance. At that point there are regulars who generally surface to help guide & decide.
In a nutshell.
 

strmrdr

Super_Ideal_Rock
Joined
Nov 1, 2003
Messages
23,295
Date: 3/4/2009 8:10:01 AM
Author: John Pollard
Date: 3/4/2009 7:58:51 AM

Author: Ellen


True enough strm. But most coming on here are not looking for the 'other' beauties (and those few who are, usually say so), so this just helps narrow down/ease the search process for newbs.To elaborate on, and list all the caveats to get other cuts that are worthwhile, would just add stress and confusion to the process. imho
Indeed Ellen. That was the reason the 'Cliff's Notes' surfaced. To stop parroting same-info over and over to newbs looking at dubious combos...getting them back onto a well agreed-upon road.


Karl is saying there are other scenic routes. It's true, but those roads are less certain and often require specific guidance. At that point there are regulars who generally surface to help guide & decide.
I like the idea behind them that they are incomplete is what bugs me.
Maybe you me and Garry need to put our heads together and present a better version when everyone has time.
Since 2 out of 3 is traveling right now lets plan on doing so when everyone is back home.
I think we can add 3-4 lines that will bring the others into the fold without getting 2 confusing.
I do not want to go back to the days when near-tolk was the only considered and I see that happening now.
 

Lorelei

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
42,064
Date: 3/4/2009 12:12:16 PM
Author: strmrdr

Date: 3/4/2009 8:10:01 AM
Author: John Pollard

Date: 3/4/2009 7:58:51 AM

Author: Ellen


True enough strm. But most coming on here are not looking for the ''other'' beauties (and those few who are, usually say so), so this just helps narrow down/ease the search process for newbs.To elaborate on, and list all the caveats to get other cuts that are worthwhile, would just add stress and confusion to the process. imho
Indeed Ellen. That was the reason the ''Cliff''s Notes'' surfaced. To stop parroting same-info over and over to newbs looking at dubious combos...getting them back onto a well agreed-upon road.


Karl is saying there are other scenic routes. It''s true, but those roads are less certain and often require specific guidance. At that point there are regulars who generally surface to help guide & decide.
I like the idea behind them that they are incomplete is what bugs me.
Maybe you me and Garry need to put our heads together and present a better version when everyone has time.
Since 2 out of 3 is traveling right now lets plan on doing so when everyone is back home.
I think we can add 3-4 lines that will bring the others into the fold without getting 2 confusing.
I do not want to go back to the days when near-tolk was the only considered and I see that happening now.
Sounds like a plan if it can be done in a way which isn''t confusing to newcomers.
 
Status
Not open for further replies. Please create a new topic or request for this thread to be opened.
Be a part of the community It's free, join today!
    What is White Gold?
    What is White Gold?
    Push Present: Engagement Ring Upgrade
    Push Present: Engagement Ring Upgrade
    20th Anniversary Upgrade
    20th Anniversary Upgrade

Need Something Special?

Get a quote from multiple trusted and vetted jewelers.

Holloway Cut Advisor



Diamond Eye Candy

Click to view full-size image.
Top