Peer review of Cutting standards by AGS

Here is part of the continuing conversation about cutting going on the Polygon site. This is the response to a gentleman stating that Tolkowski had the advantage of peer review when he wrote his thesis on diamond cutting in the early 1900's.

Turns out that the AGS had extensive peer review, even if they did not make a lot of noise about it!

Wink

Bill, I hate to correct you on this, but you are wrong. As
you know I chaired the Gemological Sciences Committee during
the time we were coming up with the cut grade system for the
AGS Laboratory. Let me tell you about peer involvement and
review.

First, the chairman of the committee has a Ph.D. in
inorganic chemistry with an extensive background in research
at the university level (just happens to be me).

Second, the committee consisted of jewelers with scientific
backgrounds, cutters, retailers, suppliers, lab people, etc.

Third, in keeping with scientific protocol we approached the
problem from two standpoints-theoretical and experimental.

Fourth, our experimental work was guided by a Ph.D. in
optics who heads up optical research at one of our nations
finest universities.

Fifth, our theoretical work was carried out by a team of
scientists from a foreign university well known for work in
this field.

Sixth, also in keeping with scientific protocol for
acceptance of scientific developments and material for
publication we employed a peer reviewer to look over the
shoulders of what the other two groups were doing(augmented
by work done by employees of the AGS Laboratory). We were
adamant that no system would be implemented until such time
as the peer reviewer put in writing that our science was
impeccable and that we were clear, from a scientific
standpoint, to go public. That peer reviewer was a
distinguished professor in optics at a different university
and editor of a major journal in that field.

Seventh, so much for the science. What all that yielded was
mountains of paperwork with both theoretical calculations
and actual measurements on the behavior of light in crystal
systems. The results were made graphic in contour diagrams
that showed the different dimensions and angles that
represented the maximum return of light, taking into
consideration a multitude of environmental factors. Now,
here's the kicker, during the years we studied those
experimental/theoretical diagrams, one person on the
committee kept reminding us over and over again with
statements like, "yes, that particular configuration does
seem to handle light better than others, BUT will that stone
appear to be beautiful to the eye."

I should also point out that it took the committee several
years to arrive at the AGS cut grading standards.

One amazing discovery came out of all that work. After all
the science is applied to the system, when one looks at the
areas on the contour diagram where light seems to be handled
best, right in the center of that area sits Mr. Tolkowsky's
ideal cut.
What all this leads to is the circumstance that when a
jeweler is getting ready to show a customer a diamond that
has the AGS triple zero designation, and even before the
paper is opened, he can be assured that the diamond has been
cut to the most exacting of geometric proportions and that
it will be beautiful to look at.

Perhaps others on this board with knowledge of how the other
laboratories arrived at their cut grading standards would be
willing to share that with the rest of us.

Chris Bramlett