Details the process used by Wiede’s Carbidwerk to produce star synthetic corundum from the mid-1950s until the 1970s.
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Describes the occurrence of iridescence, and the role of differential etching, in quartz crystals from India’s Jalgaon District.
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Describes the phenomenon of pleochroism and its complex effect on the appearance of coloured stones.
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Investigates the presence of fluorescence, rather than iridescence, as the cause of colour in blue amber from the Dominican Republic and Indonesia.
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How contrast patterns can increase perceived brightness and optimise a gemstone's appearance.
Read MoreModern gemmologists and diamantaires are faced with a broad spectrum of colour and clarity treatments ranging from the simple to the highly sophisticated.
Read MoreUsing a multi-step process, Lucent Diamonds has developed a new treatment process for certain natural diamonds that creates colours from pink-purple to red to orangey brown.
Read MoreThis second major article in a three-dimensional modelling study analyses fire – the visible extent of light dispersed into spectral colours.
Read MoreOne of the greatest concerns with emerald filling is the degree of clarity enhancement such treatment represents
Read MoreMillions of carats of turquoise have been enhanced by a proprietary process called the Zachery treatment.
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