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.
Mining Diamonds in the Canadian Arctic: The Diavik Mine
Located near the Arctic Circle, Diavik is one of the world’s richest diamond deposits and a leader in sustainable mining.
Reversible Colour Modification of Blue Zircon by Long-Wave Ultraviolet Radiation
Determines whether blue zircon, inadvertently altered to brown by exposure to long-wave UV radiation, can be restored to its original colour through the use of incandescent light.
Jaipur, India: The Global Gem and Jewellery Power of the Pink City
Examines Jaipur’s role as a coloured stone cutting and jewellery manufacturing centre, with profiles of 17 companies and their factory, trading and retail operations.
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.
Observations on CVD-Grown Synthetic Diamonds: A Review
Explores statistical data and defining characteristics of gem-quality CVD synthetic diamonds examined by GIA since 2003.
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.
Vanadium and Chromium-Bearing Pink Pyrope Garnet: Characterisation and Quantitative Colorimetric Analysis
This type of pink pyrope garnet, believed to have been mined in Tanzania, shows a distinct colour-change phenomenon resulting from its unique chemical composition.
Letšeng’s Unique Diamond Proposition
Explores the history, geology and current production of this unique source of large diamonds.
Gemmological Characterisation of Sapphires from Yogo Gulch, Montana
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.