World Gem Foundation: Reveals Diamond Clarity Grading Math Success
Gary Roskin –
Roskin Gem News Report –
In the latest issue of the World Gem Foundation’s magazine, Gemmology Today, founder and editor Geoff Dominy puts together another very interesting read. What caught our attention was Dominy’s review of Michael Cowing’s objective diamond grading system: “More or Less – Objective Diamond Clarity Grading.”
Michael Cowing is an expert in all things diamond, diamond cut, diamond color, diamond fluorescence, and diamond grading. His book, Objective Diamond Clarity Grading, proves that he is not only an exceptional diamond grader, but he has head for math.
And this leads us to GIA, the Gemological Institute of America, describing diamond grading as an “art and a science.”
2 x 2 x 2
What if we were to say that diamond clarity grading isn’t actually art. What we would like you to consider is this – that Clarity Grading is math.
“Our right brain is thinking it is art, but our left brain is doing the math!” says Gary Roskin, author of Photo Masters for Diamond Grading – and publisher of the Roskin Gem News Report. “And it is all based upon the Fibonacci golden spiral.” [In geometry, a golden spiral is a logarithmic spiral whose growth factor is φ, the golden ratio. That is, a golden spiral gets wider by a factor of φ for every quarter turn it makes.]
“What I am saying is that when we look at an inclusion in a diamond, we see it’s size in relation to the size of the diamond. We tell ourselves that the inclusion is small, or medium sized, or large, and then we make ‘an artistic subjective judgement’ as to whether it is VVS, VS, SI, or I in grade. What Michael has done is to take that little Fibonacci left brain idea and create the math. He has developed the math that sets the grade, based upon the golden spiral, where the space that the inclusion occupies increases with every grade.”
And it works!
“What Michael and I have discussed over the years is that the diamond graders of the 1940s, when developing GIA’s clarity grading scale, they looked at an inclusion and pronounced how obvious it was compared to the size of the diamond. Their right side of the brain was saying “this looks right” while their left side of the brain was working out the math.”
[It’s probably what Sarine is using to assist AI clarity grading. – gr]
Geoff Dominy and the World Gem Foundation is the first to use this idea in training a class of beginning diamond graders, to use Cowing’s math, along with traditional methods, and graduate a class of proficient diamond graders.
You can read his review of the program in this issue of Gemmology Today here!
