AGS Gets Proportion-al


Regarding the AGS’ decision to introduce a new “proportion-based” cut grade system, I spoke on Wednesday to AGS lab honchos Peter Yantzer and Frank Dallahan.


At first glance, the lab’s decision is surprising, considering how much of its identity is tied up in its unique cut grade. But Dallahan says the idea is to provide a grade that people can “understand.”


“95% of the world understands proportion-based grading,” he told me. “But only 5% understand performance systems. Those who do understand it love it. But for many it doesn’t fit their mode of operation.”


Which brings us to the AGS’ new system, which, like GIA’s, is proportion-based. It will be offered on the AGS’ “gold” report, while the old “performance-based” system will be offered on its “platinum” reports.


What’s interesting here is, a decade or so after the AGS had a dramatic impact on diamond cutting with its “AGS zero,” it is now offering a system that uses, like GIA’s system, a range of adjectives, from “ideal” on down. (The grades will be: “Ideal,” “excellent,” “very good,” “good,” “fair” and “poor.”) The platinum reports will still use the zero to ten model.


Other points:

– It will be somewhat harder to get a “zero” on the platinum report than to get an “ideal” on the gold.


– Tolkowsky-based “Ideal” cuts will be among those getting top grades on both systems.


– The proportion-based grading system was in part derived from the performance-based system.


This certainly makes sense from AGS’ point of view, but it also raises the issue: Is there a need for the industry to move to a standardized system of grading cut, like we have for color and clarity? And is there a risk of consumer confusion with all these systems out there, especially since one lab now has two?


JCK News Director