Spring 2015 G&G Examines Blue Spinel, Chinese Jewellery Design and the Latest in Synthetics
G&G Brief presents an overview of the content of the Spring 2015 issue of Gems & Gemology.
Spring 1991 G&G Lab Notes
This section, from the Spring 1991 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Green Sapphire Filled with Glass
Analysis reveals blue lead glass filling in a sapphire that has an overall green bodycolour as a result of the filling’s combination with natural yellow colour.
Yellow Synthetic Sapphire Coloured by Trapped-Hole Mechanism
A combination of trace-element analysis and UV-visible spectroscopy clearly indicated that the yellow colour originated from the much more effective chromophore known as “trapped holes” associated with the trace amount of Mg and Cr in this stone.