Pleochroism in Faceted Gems: An Introduction
Richard W. Hughes, October 31, 2014
Describes the phenomenon of pleochroism and its complex effect on the appearance of coloured stones.
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Titanium-Coated Tanzanite
Amy Cooper and Nathan Renfro, April 30, 2014
For the first time, GIA's laboratory has examined tanzanite colour-coated with titanium.
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