John M. King, December 1, 2008
This article discusses the history and ongoing development of GIA's colour grading system, and explains how its laboratory applies it.
Read MoreThomas W. Overton and James E. Shigley, March 1, 2008
Modern gemmologists and diamantaires are faced with a broad spectrum of colour and clarity treatments ranging from the simple to the highly sophisticated.
Read MoreJohn M. King, December 1, 2006
This article reviews the GIA Laboratory’s history of reporting on certain types of graining which are often the only characteristics present in large, high-clarity, high-colour diamonds.
Read MoreChristopher P. Smith and George Bosshart, March 1, 2002
This article presents the first complete gemmological characterisation of the historic 128.48 ct Brazilian diamond known as the Star of the South.
Read MoreIlene M. Reinitz, Mary L. Johnson, September 1, 2001
This second major article in a three-dimensional modelling study analyses fire – the visible extent of light dispersed into spectral colours.
Read MoreC. W. Fryer and John I. Koivula, June 1, 1986
Several famous and historical gemstones in the Smithsonian's collection are examined and reported on.
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