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.
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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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A simple chart of optical defects in diamond, including those that produce colouration and fluorescence colours.
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How variations in UV lamp output can affect observed fluorescence colour and intensity.
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The past decade saw some impressive discoveries of diamonds and coloured stones.
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A new microlithography process developed to create high-resolution diffraction grating patterns on portions of certain facets can improve the dispersion of light and thus the amount of “fire” in a diamond.
Read MoreNapoléon Bonaparte gave an extraordinary diamond necklace to his empress, Marie-Louise, in 1811.
Read MoreThe GIA diamond cut grading system described here includes the components of brightness, fire, scintillation, polish and symmetry, as well as weight and durability concerns, into a single overall grade for cut quality for standard round brilliants.
Read MoreThis section, from the Winter 2011 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
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