Monday, May 7, 2012

Diamonds Part 4: CUT

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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