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This article discusses the history and ongoing development of GIA's colour grading system, and explains how its laboratory applies it.
Read MoreModern gemmologists and diamantaires are faced with a broad spectrum of colour and clarity treatments ranging from the simple to the highly sophisticated.
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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 MoreThis article presents the first complete gemmological characterisation of the historic 128.48 ct Brazilian diamond known as the Star of the South.
Read MoreThis second major article in a three-dimensional modelling study analyses fire – the visible extent of light dispersed into spectral colours.
Read MoreSeveral famous and historical gemstones in the Smithsonian's collection are examined and reported on.
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