Fluorescence produced by optical defects in diamond: measurement, characterisation and challenges
How variations in UV lamp output can affect observed fluorescence colour and intensity.
The “Type” Classification System of Diamonds and Its Importance in Gemmology
Knowledge of type allows gemmologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.
Abstracts; Summer 2009
This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
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.
GE POL Diamonds: Before and After
This article explores and identifies the changes that type IIa GE POL diamonds experience before and after HPHT annealing.
A Visual Guide to the Identification of Filled Diamonds
This article illustrates the various features in filled diamonds and explores the best techniques for examining them.
GIA’s Symmetry Grading Boundaries for Round Brilliant Cut Diamonds
A presentation of parameters used to support GIA's symmetry grading system.
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.
Fingerprinting of Two Diamonds Cut from the Same Rough
With the information from a combination of tools now available, the sophisticated gemmologist can fingerprint a given stone.
Modern Diamond Cutting and Polishing
Over the last 25 years, the diamond-cutting industry worldwide has been revolutionised by sophisticated instruments that provide invaluable aid in the process of creating a polished gem.