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 MoreDescribes the occurrence of iridescence, and the role of differential etching, in quartz crystals from India’s Jalgaon District.
Read MoreExamines a collection of chrysoberyl samples from these sapphire placer deposits to determine their distinct mineralogical and chemical properties.
Read MoreAn introduction to Moroccan amethyst, which features distinctive color zoning and inclusions.
Read MoreDescribes the phenomenon of pleochroism and its complex effect on the appearance of coloured stones.
Read MoreHow contrast patterns can increase perceived brightness and optimise a gemstone's appearance.
Read MoreHow variations in UV lamp output can affect observed fluorescence colour and intensity.
Read MoreA simple chart of optical defects in diamond, including those that produce colouration and fluorescence colours.
Read MoreKnowledge of type allows gemmologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.
Read MoreThis article reviews the GIA Laboratory’s history of reporting on certain types of graining which are often the only characteristics present in large, high-clarity, high-colour diamonds.
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