Colour Grading “D-to-Z” Diamonds at the GIA Laboratory
This article discusses the history and ongoing development of GIA's colour grading system, and explains how its laboratory applies it.
A History of Diamond Treatments
Modern gemmologists and diamantaires are faced with a broad spectrum of colour and clarity treatments ranging from the simple to the highly sophisticated.
The Impact of Internal Whitish And Reflective Graining on the Clarity Grading of D-To-Z Colour Diamonds at the GIA Laboratory
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.
Star of the South: A Historic 128 Ct Diamond
This article presents the first complete gemmological characterisation of the historic 128.48 ct Brazilian diamond known as the Star of the South.
Modelling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Fire, and More about Brilliance
This second major article in a three-dimensional modelling study analyses fire – the visible extent of light dispersed into spectral colours.
An Examination of Four Important Gems
Several famous and historical gemstones in the Smithsonian's collection are examined and reported on.