AGS new cut grade system

[Garry H (Cut Nut)]

Assumptions and Aspects of the Forthcoming AGS Cut Grading System
To be presented at the First Diamond Cut Conference
Moscow 23-26th April 2004

Peter Yantzer*, Dr. Jose Sasian**, James Caudill*

* American Gem Society Laboratories, USA ** University of Arizona, USA

The American Gem Society has been studying diamond cut for several years. Our goal is to develop practical, performance-based cut grading systems for fancy shape diamonds, round brilliants and round fancies.

The AGS Research Team has utilized and combined different approaches to try to explain diamond cut. Some of these are: direct observation, angular spectrum, ray tracing virtual and wire frame models, color-coded photography, OctoNus DiamCalc software.

The new AGS System will take into account the following factors: an observer, a close viewing distance, appearance as distance varies, brilliance, fire, leakage, scintillation, ''spread'', tilt, obscuration, girdle thickness, length-to-width ratio, polish, symmetry, durability and taste.

By sharing some information on these factors we hope to:
1. Help the world cut grading community achieve a better understanding of the complex factors that affect diamond performance.
2. Fine-tune our system through constructive feedback and criticism.

Keywords: diamond, cut, research, performance

 

[eyesoftexas]

Cutnut,
Within the cut grading system will polish and symetry be included? I remember you said that someone was doing research on the effects of polish on light return and they were going to present at the conference??? Just wondering.....

 

[Garry H (Cut Nut)]

Yes, Mr Janak Mistry is doing the research at present. We are communicating - I have seen some pictures.
All will be revealed at the conference.

Eventually it is likely that symmetry will be graded based on:
1. its impact on diamond visual beauty
2. as a craftsmansship award / penalty possibly as a combined "finish" or "polishing quality".