July 19th, 2007

What is Internal Graining?

Internal Whitish Graining
A frequent question we get asked is what is Internal Graining? The attached picture is an example of whitish internal graining. It caused the diamond to lose a clarity grade. It was given a VVS1 even though it was an internal feature that was only visible at 10x power through the pavilion side of the diamond. The photo was taken by Vincent Cracco at a magnification of 21x for a GIA article about graining. By the way, graining can also happen with brownish color.

This brings up another question we get asked. Why 21x magnification? Isn’t clarity supposed to be determined by what is visible under a loupe of 10x power magnification? Yes. However, sometimes you might only be able to see an inclusion at 10x power, but not be able to identify what it is. Why is that important? There are many reasons, for example if an inclusion indicates the stone was clarity enhanced. Another example would be for detecting HPHT treatment. Another would be to determine if the inclusion causes a stability issue.






One Response to “What is Internal Graining?”

  1. SANDIP SHETA says:

    HI!
    WHY BUYER DEMAND MORE BACK(DICOUNT) IN
    Internal Graining DIAMOND REPORT.

    ITS VERY HARD TO SELL!!!

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