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 MoreDetermines 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.
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 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 MoreHow contrast patterns can increase perceived brightness and optimise a gemstone's appearance.
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.
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