A type IIa colour-treated diamond was graded as Fancy brown-pink under daylight conditions and Fancy purplish grey under incandescent lighting, a colour change that resulted from HPHT annealing and irradiation.
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Examination of a 59.88 ct irradiated yellow diamond, one of the largest irradiated diamonds identified by GIA.
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DiamondView imaging and photoluminescence spectroscopy offered evidence of focused beam irradiation in a pink diamond.
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A Fancy pink type IIa diamond showing cuboctahedral growth and greenish blue phosphorescence is shown to be a natural, treated coloured diamond.
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HPHT annealing of a nearly eye-clean yellow natural rough diamond is revealed through spectroscopic analysis.
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G&G Brief presents an overview of the content of the Spring 2015 issue of Gems & Gemology.
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A look at the first CVD synthetic diamond examined at GIA that has been irradiated to a blue colour.
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Examination of a diamond with a rare and highly sought-after Fancy reddish brown colour revealed that it had been irradiated and coated.
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The New York lab encountered another large HPHT-treated diamond that showed stronger pink colouration.
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The stone owes all of its green colour to these shallow radiation stains.
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