The standardized grading of diamonds is
a relatively recent industry development. Even after GIA established
color and clarity grades, there continued to be a missing factor in a
set of scientifically gathered information to accurately asses a
diamond for quality. The final factor, thr fourth “C” stands for
cut.
Color and clarity are inherent
properties of the diamond as it comes out of the earth, yet the cut
of the diamond is man's effort to unlock the shimmering beauty of the
stone. Because diamonds are the hardest substance on earth, cutting a
diamond in just the right was to create maximum brightness and fire
is no small feat.
After my trip to GIA at the end of
April, I have a profoundly new appreciation for the impact that a
cutter can have on the overall look of a finished diamond. I analyzed
some diamonds with excellent clarity and color grades that simply did
not seem to sparkle. One in particular just looked dark and lifeless.
When I began to measure the proportions
of the stone's depth as well as the angle and size of the facets, I
discovered that while the gem looked similar to the other diamonds,
it's proportions fell far outside of the prescribed ranges for
excellent cutting. So even though this diamond was worth a great deal
of money as rough material, the work of the cutter was of poor
quality and really damaged the potential value of the stone. It would
be very difficult to sell a diamond that just didn't seem to sparkle
like the others.
On the other extreme, a diamond which
is cut to fall within the many proportion standards for an excellent
cut grade looks like it is radiating with it's own light source! The
cut grade and proportions are based on the physics of light entering
the diamond, then bouncing around at just the right angles to come
back out the top of the stone for your viewing pleasure. The more the
light bounces around inside the stone, the more it “disperses” or
separates into different colors of the light spectrum creating what
is termed “fire” or the presence of different colors of light.
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