Identification of “Pistachio” Coloured Pearls Treated by Ballerina Pearl Co.
A report on the colour treatment process for these intensely greenish yellow to yellowish-green cultured pearls and the techniques for identifying them.
Variscite from Central Tajikistan: Preliminary Results
A look at the gemmological properties and chemical composition of this light blue to light green to green gem material, which is suitable for cabochon cutting.
Gemmological Characterisation of Sapphires from Yogo Gulch, Montana
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
An Early Byzantine Engraved Almandine from the Garibpet Deposit, Telangana State, India: Evidence for Garnet Trade Along the Ancient Maritime Silk Road
Analyses the chemical composition and inclusion characteristics of this ancient artefact.
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.
The Very Deep Origin of the World’s Biggest Diamonds
Explores an exceptional family of diamonds, referred to as “CLIPPIR” (Cullinan-like, Large, Inclusion-Poor, Pure, Irregular and Resorbed), that formed in a super-deep environment.
True Colours of “Dalmatian Jasper”
Discusses the mineralogical composition and provenance of this spotted decorative gemstone.
Synthetic Star Sapphires and Rubies Produced by Wiede’s Carbidwerk, Freyung, Germany
Details the process used by Wiede’s Carbidwerk to produce star synthetic corundum from the mid-1950s until the 1970s.
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.