Evidence of Focused Beam Irradiation in Treated Pink Diamond
DiamondView imaging and photoluminescence spectroscopy offered evidence of focused beam irradiation in a pink diamond.
Very Large Artificially Irradiated Yellow Diamond
Examination of a 59.88 ct irradiated yellow diamond, one of the largest irradiated diamonds identified by GIA.
Treated Pink Type IIa Diamond Coloured by Red Luminescence
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.
Treated Pink Diamond with HPHT Synthetic Growth Structure
A Fancy pink type IIa diamond showing cuboctahedral growth and greenish blue phosphorescence is shown to be a natural, treated coloured diamond.
Yellow HPHT-Processed Rough Diamond
HPHT annealing of a nearly eye-clean yellow natural rough diamond is revealed through spectroscopic analysis.
Spring 2015 G&G Examines Blue Spinel, Chinese Jewellery Design and the Latest in Synthetics
G&G Brief presents an overview of the content of the Spring 2015 issue of Gems & Gemology.
Heavily Irradiated CVD Synthetic Diamond
A look at the first CVD synthetic diamond examined at GIA that has been irradiated to a blue colour.
Diamond, Artificially Irradiated and Coated Brown
Examination of a diamond with a rare and highly sought-after Fancy reddish brown colour revealed that it had been irradiated and coated.
Large HPHT-Treated Fancy Pink Diamond
The New York lab encountered another large HPHT-treated diamond that showed stronger pink colouration.
Green Diamond Treated with Radioactive Salt
The stone owes all of its green colour to these shallow radiation stains.