JohnQuixote
Ideal_Rock
- Joined
- Sep 9, 2004
- Messages
- 5,212
Seeing 2 threads on this subject, I thought it might be good to have a reset for further discussion on this simple, but meaningful word.
The term ‘Ideal’
AGS introduced the term on grading reports in 1996. Over the last decade ‘Ideal’ has fallen into the trade lexicon as simply meaning a round with AGS Ideal proportions. AGS has not contested outside use, which has worked to their advantage since widespread use has elevated its prominence.
However, the term has been diluted at times. EGL introduced a ‘Tolkowsky Ideal’ grade with wider proportions than the AGS Ideal. Sellers may use definitions that may not be as strict as standards introduced by AGS. In severe examples diamonds have even been advertised as ‘Ideal’ based on simple depth/table measurements.
In common parlance, we believe that round diamonds advertised with the word ‘Ideal’ (when not accompanied by an AGS document) should be expected to conform to either the old AGS Ideal proportions range (1996-2005), or new AGS proprietary grading.
Consumers should be made aware that polish and symmetry grades are part of the overall evaluation at AGS where the term originated: A diamond with traditional ‘Ideal’ proportions still may not receive ‘Ideal’ in overall cut evaluation if submitted to the AGS if its polish/sym are sym.
The term ‘AGS Ideal’
Using the term ‘AGS Ideal’ or ‘AGS 0’ is a matter of more strictness: The American Gem Society licenses its grading system to AGSL. The only people authorized to use the AGS grading system are:
• Members of the American Gem Society
• AGSL
This from the AGS: "A seller can represent a diamond as being an AGS Ideal 0 if they back it up with an AGSL report. They can also represent a diamond as being an AGS Ideal 0 if they are a member of the American Gem Society - with or without an AGSL report. If not a member of the American Gem Society, one can’t legally or ethically represent a diamond as an 'AGS Ideal' without an AGSL report."
Therefore, any diamond you see using the term AGS 0 or Ideal as part of its advertising should be accompanied by an AGS grading report, or have been assessed by an AGS member using the PGS (proprietary grading software).
Fancy Shapes
I don’t blame Paul for being protective of fancy shapes: The term ‘Ideal’ for princess, and now square emerald cuts (oval coming soon) can only be awarded by the AGSL via direct light performance metric. Unlike rounds (where ‘Ideal’ can mean traditional ideal proportions) use of the word ideal is inappropriate unless that fancy shaped diamond is accompanied by an AGSL report – or the assessor is a member of the AGS.
* By the way, in March 07 AGS will stop issuing DQDs for rounds based on proportions. At that time ‘Ideal’ will be completely performance-based for all shapes.
More information: http://www.agslab.com/faqs.html
Having said all of this: Over the years our website has grown. Though we constantly try to stay current and to avoid misunderstandings it may be possible to find something that may seem contrary or unclear. If so, please contact us so that we may better clarify or correct it. I think most Pricescope professionals will agree that consistently high standards and transparency are vital to acquiring reputability in this trade - particularly on the internet, where information is king.
The term ‘Ideal’
AGS introduced the term on grading reports in 1996. Over the last decade ‘Ideal’ has fallen into the trade lexicon as simply meaning a round with AGS Ideal proportions. AGS has not contested outside use, which has worked to their advantage since widespread use has elevated its prominence.
However, the term has been diluted at times. EGL introduced a ‘Tolkowsky Ideal’ grade with wider proportions than the AGS Ideal. Sellers may use definitions that may not be as strict as standards introduced by AGS. In severe examples diamonds have even been advertised as ‘Ideal’ based on simple depth/table measurements.

In common parlance, we believe that round diamonds advertised with the word ‘Ideal’ (when not accompanied by an AGS document) should be expected to conform to either the old AGS Ideal proportions range (1996-2005), or new AGS proprietary grading.
Consumers should be made aware that polish and symmetry grades are part of the overall evaluation at AGS where the term originated: A diamond with traditional ‘Ideal’ proportions still may not receive ‘Ideal’ in overall cut evaluation if submitted to the AGS if its polish/sym are sym.
The term ‘AGS Ideal’
Using the term ‘AGS Ideal’ or ‘AGS 0’ is a matter of more strictness: The American Gem Society licenses its grading system to AGSL. The only people authorized to use the AGS grading system are:
• Members of the American Gem Society
• AGSL
This from the AGS: "A seller can represent a diamond as being an AGS Ideal 0 if they back it up with an AGSL report. They can also represent a diamond as being an AGS Ideal 0 if they are a member of the American Gem Society - with or without an AGSL report. If not a member of the American Gem Society, one can’t legally or ethically represent a diamond as an 'AGS Ideal' without an AGSL report."
Therefore, any diamond you see using the term AGS 0 or Ideal as part of its advertising should be accompanied by an AGS grading report, or have been assessed by an AGS member using the PGS (proprietary grading software).
Fancy Shapes
I don’t blame Paul for being protective of fancy shapes: The term ‘Ideal’ for princess, and now square emerald cuts (oval coming soon) can only be awarded by the AGSL via direct light performance metric. Unlike rounds (where ‘Ideal’ can mean traditional ideal proportions) use of the word ideal is inappropriate unless that fancy shaped diamond is accompanied by an AGSL report – or the assessor is a member of the AGS.
* By the way, in March 07 AGS will stop issuing DQDs for rounds based on proportions. At that time ‘Ideal’ will be completely performance-based for all shapes.
More information: http://www.agslab.com/faqs.html
Having said all of this: Over the years our website has grown. Though we constantly try to stay current and to avoid misunderstandings it may be possible to find something that may seem contrary or unclear. If so, please contact us so that we may better clarify or correct it. I think most Pricescope professionals will agree that consistently high standards and transparency are vital to acquiring reputability in this trade - particularly on the internet, where information is king.