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.
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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.
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A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
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Characterises a suite of 40 natural brown to black diamonds from this deposit so that they can be distinguished from suspected treated black diamonds.
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Summarises data collected on more than 15,000 natural blue/grey/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this colour range.
Read MorePresents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.
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Explores an exceptional family of diamonds, referred to as “CLIPPIR” (Cullinan-like, Large, Inclusion-Poor, Pure, Irregular and Resorbed), that formed in a super-deep environment.
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Discusses the mineralogical composition and provenance of this spotted decorative gemstone.
Read MoreExamines 85 saltwater natural pearls, reportedly harvested from the Caribbean islands off the coast of Venezuela during the early 16th century, to determine their age.
Read MoreEvaluates the usefulness of Raman spectroscopy in distinguishing the colour varieties of nephrite based on the relative ratio of Mg to Fe concentration.
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