Characterises a suite of 40 natural brown to black diamonds from this deposit so that they can be distinguished from suspected treated black diamonds.
Read MoreSummarises 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 MoreExplores 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.
Read MoreA simple chart of optical defects in diamond, including those that produce colouration and fluorescence colours.
Read MoreHow variations in UV lamp output can affect observed fluorescence colour and intensity.
Read MoreThe past decade saw some impressive discoveries of diamonds and coloured stones.
Read MoreA 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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