Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards
Presents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.
Real-Time Microradiography of Pearls: A Comparison Between Detectors
Compares the image quality provided by real-time microradiographic imaging (RTX) units fitted with two different detectors: an image intensifier (II) and a flat panel detector (FPD).
Photoluminescence Spectra of Emeralds from Colombia, Afghanistan and Zambia
Compares PL spectroscopy data of 48 emerald samples from three countries to evaluate the usefulness of the technique in geographic origin determination.
An Introduction to Photoluminescence Spectroscopy for Diamond and Its Applications in Gemmology
Presents the underlying physics and methodology of this analytical technique, which has become an essential tool in identifying treated and synthetic diamonds.
Book Review: From a Snowflake to an Iceberg: The McFerrin Collection
By Dorothy McFerrin, publ. by the McFerrin Foundation, College Station, Texas, 2013, US $125 (£74)
Fluorescence produced by optical defects in diamond: measurement, characterisation and challenges
How variations in UV lamp output can affect observed fluorescence colour and intensity.
GIA’s Symmetry Grading Boundaries for Round Brilliant Cut Diamonds
A presentation of parameters used to support GIA's symmetry grading system.
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.
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.
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.