Pleochroism in Faceted Gems: An Introduction
Describes the phenomenon of pleochroism and its complex effect on the appearance of coloured stones.
An Update on “Paraíba” Tourmaline from Brazil
“Paraíba” tourmalines continue to be recovered in small amounts from north-eastern Brazil.
Multicoloured Bismuth-bearing Tourmaline from Lundazi, Zambia
Tourmalines from an alluvial deposit near Lundazi in Zambia consist of colour-zoned pink/colourless/yellow-green “watermelon” nodules.
Interesting Red Tourmaline from Zambia
A new source of red tourmaline is identified in Zambia.
Spectral Differentiation Between Copper and Iron Colourants in Gem Tourmalines
The authors used Vis-NIR spectral measurements combined with LA-ICP-MS data to investigate the usefulness of absorption spectra.
Solution-Generated Pink Colour Surrounding Growth Tubes and Cracks in Blue to Blue-Green Copper-Bearing Tourmalines from Mozambique
Several transparent, faceted, blue to blue-green copper-bearing tourmalines containing growth tubes and cracks surrounded by sleeves of pink colour were examined for this report.