|They said it couldn't be done: Objective Clarity Grading
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|Author:||michaelgem [ Tue Mar 28, 2017 6:17 pm ]|
|Post subject:||They said it couldn't be done: Objective Clarity Grading|
They said it couldn't be done: Objective Diamond Clarity Grading
Thrilled to unveil Michael Cowing's new digital e-book on
Objective Diamond Clarity Grading.
This new book alters the ‘playing field’ by
introducing a system that removes the subjectivity of diamond clarity grading.
Now it is even possible for 'novice' diamond clarity graders to reach a level
of consistency that up until now has only been possible after years of
experience and the examination of thousands of diamonds.
With over 250 images, Objective Diamond Clarity Grading is
an A to Z on how to clarity grade diamonds and have the confidence that you
will not only arrive at the right conclusions but have a systematic method and
procedure that will back up your grades.
It's just $19.95! This book has been in the planning
stages for many years but the information is as relevant today as it was when
Michael started this project. It will not only change the way we think but will
make our industry stronger and far more credible.
Buy it now at http://www.amazonasgempublications.com/odcg.html
Foreword by Gary Roskin
Measuring inclusions to determine a clarity grade has been
an idea for as long as I can remember, which in actual years puts us back into
the late 1970s. It was during that period of my young gemological career when I
overheard a conversation between Richard Liddicoat, then president of GIA, and
Dennis Foltz, then GIA director of education. They were talking about measuring
inclusions, using such equipment as rotating stone holders, and referring to
Okuda’s and Huddlestone’s mathematical work. I do not recall ever seeing the
measuring of inclusions as part of the teachings of diamond grading, but the
idea of it was something I had never forgotten.
It wasn’t until the early 1990s when I started working again
with Tom Tashey, then owner of the Los Angeles European Gem Lab, that the idea
of measuring inclusions became reality. Tom, who just happened to be my diamond
grading supervisor at the Santa Monica GIA Gem Trade Laboratory in the late
1970s, had us using a small transparent plastic grid (transparent plastic
“graph paper”) to measure the approximate size of an included crystal. It was
certainly limited in nature, but it worked well enough to keep us consistent
and that’s what diamond grading is all about, remaining consistent.
Over the years, Michael’s quest for finding an objective
mathematical truth to diamond grading has been un-daunting. I remember our
conversations starting with color grading, as Michael was trying to figure out
mathematically how the grade ranges could be defined. This of course then led
to talking about clarity grade ranges, how these too might be mathematically
And that’s where Fibonacci and the Golden Spiral and Ratio
come in. I was watching a presentation I believe at a Gem-A conference, or was
it Diana Singer, New York jewelry historian and Estate Jewelry expert, talking
about the Golden Ratio symmetry in a period piece, relating the beauty of an
object as perceived to how the brain has calculated it as being aesthetically
correct and mathematically appropriate. We say “beautiful” when our brain
perceives that an art object is mathematically and aesthetically correct, as it
is when proportions align with the Golden Ratio and the Fibonacci spiral.
Michael and I have been talking about the subjective and
objective aspects of diamond grading for years. Anyone who has spent more than
five minutes with Michael talking about the GIA’s diamond grading system has
seen and heard Michael’s frustration with understanding clarity grading’s
subjective and unscientific underpinnings.
Though they were experts in diamond grading, it was quite
literally developed by “a bunch of guys sitting around the table saying things
like ‘that looks like a solid SI1 to me. What about you?’“ This then led us
directly to the question in our discussion, why? What is it that makes us feel
that SI1 is more appropriate than any other grade?
What is it in our head, when looking at an emerald cut or a
pear shape that says to us that the shape is “just right” or “too long” or some
such seemingly subjective comment? How do we do that? I would submit that it’s
our brain, in some sense mathematically determining the proportions of the
stone, and liking proportions close to those in nature that obey ratios like
Fibonacci’s. Whether it’s about symmetry of shape, the noticeable amount of
color, or the visibility of an inclusion, our mathematical brain is signaling
us to make a seemingly subjective comment, to say “it looks like a high VS2 to
Our discussions eventually led us to talking about a sort of
Golden Spiral of clarity grades like the Fibonacci Golden Spiral, but where the
Golden Ratio relating clarity grades is 2 to 1 rather than 1.62 to 1.
Leave it to Michael to grab on to the math of the Spiral and
doggedly work it until he could present a mathematical method for consistent
Michael’s historical research with Okuda and especially with
Roy Huddleston, endeavoring to prove or correct their work, and then to refine
the mathematical algorithm to give us a solid way to objectively clarity grade
a diamond, is quite possibly the most significant leap forward towards
developing the black box for consistent diamond clarity grading. We still
believe that diamond grading is as much an art as it is a science, but what
Michael has actually accomplished is to greatly increase the amount of science
(the consistency) and he has revealed the natural mathematical underpinnings to
the art (the subjectivity) with his System and the discovery of the “Golden
Ratio of Clarity Grading.”
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