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.
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.
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.
Origin Determination of Dolomite-Related White Nephrite through Iterative-Binary Linear Discriminant Analysis
A technique for origin identification based on statistical analysis and LA-ICP-MS spectrometry.
Characterisation of Mg and Fe Contents in Nephrite Using Raman Spectroscopy
Evaluates the usefulness of Raman spectroscopy in distinguishing the colour varieties of nephrite based on the relative ratio of Mg to Fe concentration.
Fluorescence produced by optical defects in diamond: measurement, characterisation and challenges
How variations in UV lamp output can affect observed fluorescence colour and intensity.
Useful Visual Clue Indicating Corundum Heat Treatment
A demonstration of the conversion of limonitic residues to hematite in surface-reaching.
Cutting Diffraction Gratings to Improve Dispersion (“Fire”) in Diamonds
A new microlithography process developed to create high-resolution diffraction grating patterns on portions of certain facets can improve the dispersion of light and thus the amount of “fire” in a diamond.
Characterisation of “Green Amber” With Infrared and Nuclear Magnetic Resonance Spectroscopy
A peridot-like bright greenish yellow to green gem material called “green amber” has recently appeared in the gem market.
Gem-Quality Andalusite from Brazil
Widely known as a rock-forming mineral, andalusite is not frequently encountered as a gem material.