Have you ever wondered why two diamond dealers sitting on the same side of the table are not always able to give the same value for a diamond?
The answer lies in the way this business is done the world over, most dealers come form the traditional school, where quality approximation, rather than "standards" rule the roost. The gemological institute of America GIA, long considered the Mecca for training in this field devised a scale for standardized grading of diamonds 4C's-Carat, Color, Clarity, Cut-together account for the value of diamond.
In this context, the Rapaport price index goes a significant way in relating quality with value.Rapport tables allot specific quality grades to carat, color and clarity while determining value. But only give a general description of cut quality. Why? Is cut of less relevance to diamonds value, or is it that they don't have an answer? If luster & appearance, as is generally accepted are the two factors that equally account for diamond value, let us appreciate the individual contribution of 4Cs-to them.
Appearance as can be made out is affected in equal measure by each of the 4Cs-carat makes diamonds look bigger, better clarity betters purity of vision Preferred hues & tones of color are directly related to the viewers sense of beauty Ideal cut ensures shape and faceting style preference ideal faceting quality.
From this we can hypothetically allocate each C with 12.5 percentage points for contribution to diamond quality out of the total 50% that is determined by appearance.
What about the other 50% that is a accounted for by its luster?
It is common knowledge that diamond cut includes Shape: Rounds, Fancies & Fanciful Faceting style: whether Brilliant, step, Mixed, Modified or Modern Quality of faceting: with each shape having its own parameters for ideal proportions,, make and shape appeal. As the other Cs has little bearing when it comes to luster, it is usually the diamonds cut alone that accounts for the 50 percentage points devolved to luster. So we see how the 4th C-Cut usually influences diamond value by a total of 62.5 percentage points. But, where is the "one" consolidated answer to this most vital of the 4Cs? Why do two stones with the same quality grades on the rapport vary so highly in value?