Inclusions in Natural, Synthetic and Treated Ruby
Provides a visual guide to the internal features of natural, synthetic and treated rubies.
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.
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.
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.
Experimental Studies on the Heat Treatment of Baltic Amber
Amber samples were heat-treated, using various procedures and parameters, in an effort to reproduce materials found in the jewellery market.
CVD Synthetic Diamonds from Gemesis Corp
An examination of the gemmological and spectroscopic properties of CVD synthetic diamonds from Gemesis Corp.
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.
A History of Diamond Treatments
Modern gemmologists and diamantaires are faced with a broad spectrum of colour and clarity treatments ranging from the simple to the highly sophisticated.
Coated Pink Diamond — A Cautionary Tale
The Diamond Trading Company (DTC) Research Centre had the opportunity to examine a diamond that, on submission to a commercial gem laboratory, turned out to be a coated pink diamond.
A Gemmological Study of a Collection of Chameleon Diamonds
Chameleon diamonds are among the rarest of gem diamonds.