Feature Gems & Gemology, Summer 2002, Vol. 38, No. 2

Characterization and Grading of Natural-Color Pink Diamonds

John M. King, James E. Shigley, Scott S. Guhin, Thomas H. Gelb, and Matthew Hall

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The GIA Gem Trade Laboratory (GTL) collected gemological data on 1,490 natural-color pink gem diamonds—both types I and II. While there was some overlap in gemological properties between the two diamond types, they did show differences in their color ranges, ultraviolet fluorescence, absorption spectra, and microscopic features. The color description terminology used for pink diamonds on GIA GTL grading reports is discussed and illustrated, with a separate commentary on red diamonds.