Gem Virtuosos: The Drehers and Their Extraordinary Carvings
A look at the artistic heritage of the Drehers, an influential family of gem carvers in Idar-Oberstein, Germany.
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.
Observations on HPHT-Grown Synthetic Diamonds: A Review
Summarizes statistical data and distinctive features of several thousand gem-quality HPHT synthetic diamonds examined by GIA from 2007 through 2016.
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.
Characterization of Mg and Fe Contents in Nephrite Using Raman Spectroscopy
Evaluates the usefulness of Raman spectroscopy in distinguishing the color varieties of nephrite based on the relative ratio of Mg to Fe concentration.
Photoluminescence Mapping of Optical Defects in HPHT Synthetic Diamond
Demonstrates the importance of this method in identifying diamond treatments, based on the analysis of PL maps acquired from a brownish orange HPHT synthetic diamond.
The Identification of Blue Diffusion-Treated Sapphires
Blue diffusion-treated sapphires are becoming more prevalent than ever before.
Fluorescence Produced by Optical Defects in Diamond: Measurement, Characterization, and Challenges
How variations in UV lamp output can affect observed fluorescence color and intensity.
Seeking the Legacy of Australian Sapphire
Australia has been a prolific supplier of blue sapphire and has made enormous contributions to the global sapphire industry that still shape it today.
CVD Synthetic Diamond Over 5 Carats Identified by GIA
Results from GIA’s recent testing of a 5.19 ct CVD synthetic diamond, the largest it has examined to date.