The Gemmological Properties of the Sumitomo Gem-Quality Synthetic Yellow Diamonds
Sumitomo Electric Industries is producing gem-quality synthetic yellow diamonds in deep yellow single crystals in sizes up to 2 ct.
Natural-Colour Nonconductive Grey-to-Blue Diamonds
Two new categories of grey-to-blue diamonds are described.
Three Notable Fancy-Colour Diamonds: Purplish Red, Purple-Pink and Reddish Purple
The description and properties of three fancy-colour diamonds auctioned at Christie's.
Large HPHT-Treated Fancy Pink Diamond
The New York lab encountered another large HPHT-treated diamond that showed stronger pink colouration.
Characterisation and Grading of Natural-Colour Pink Diamonds
Known for their great beauty and rarity, pink diamonds have long been sought after by jewellers, collectors and consumers.
Grading the Hope Diamond
One of the most popular exhibits at the Smithsonian Institution, the stunning Fancy Dark greyish blue Hope diamond was formally graded by GIA’s gem laboratory.
Contribution to the Identification of Treated Coloured Diamonds: Diamonds with Peculiar Colour-Zoned Pavilions
Some treated yellow and blue-to-green diamonds show a peculiar colour zoning when viewed through the pavilion.
The Identification of Artificial Colouration in Diamond
The source of colour in some diamonds, particularly fluorescent green and some yellow stones, can be very difficult to identify despite increasing knowledge about the radiation-related bands seen in the visible spectra of diamonds.
Identification of HPHT-Treated Yellow to Green Diamonds
Greenish yellow to yellowish green HPHT-treated diamonds exhibited highly saturated body colour, well-defined brown to yellow octahedral graining and visual evidence of heating, among other characteristics.
Lab-Grown Coloured Diamonds from Chatham Created Gems
This article compares some of Chatham Created Gems’ synthetic coloured diamonds to natural diamonds and explains the results.