New Diamond Technology (NDT) has unveiled a 10.07-carat emerald-cut fancy deep blue stone, which was created using the high pressure, high temperature (HPHT) process.
The International Gemological Institute (IGI) in Antwerp certified the diamond as having SI1 clarity, “very slight” fluorescence, “very good” proportions and “very good” polish and symmetry.
NDT president Tamaz Khikhinashvili told Jeweller the company was not ready to disclose the item’s value but added “these diamonds are the next best thing to the natural”.
“The natural blue diamonds of that size or even smaller, anything over two carats really, goes from auctions for millions of dollars,” Khikhinashvili said.
“This one is intense, pure, even color and of a big size and available for much lower price than the natural.”
Khikhinashvili said NDT had discovered how to produce blue diamond crystals in a way that only needed cutting and polishing with no additional treatments or enhancements required.
The stone is said to be more than twice the size of a 5.03-carat blue synthetic diamond, produced by NDT using a high pressure, high temperature (HPHT) process and presented at the Baselworld fair in Switzerland in March this year.
According to a report by US trade publication JCK, a retailer purchased the 5.03-carat blue stone for US$250,000 (AU$326,000)who in turn sold it for an undisclosed amount.
Synthetic evolution
As previously reported by Jeweller in June 2015, NDT created a 10.02-carat square emerald-cut colourless diamond. It was one of a succession of synthetics claimed to have been at one time the “world’s biggest”.
The IGI in Hong Kong certified the type IIa stone as having VS1 clarity and E colour with a “very good to excellent” finish grade.
In February 2015, NDT produced a radiant cut, type IIa diamond, weighing 5.11 carats with K colour and SI2 clarity.
A few months prior to that, US-based Pure Grown Diamonds had staked a claim for the “world’s biggest” accolade with its near colourless, 3.04-carat round stone with I colour, SI1 clarity and a “very good cut”. Pure Grown Diamonds, however, used a different process from HPHT – known as CVP (chemical vapour deposition) – to manufacture the synthetic stone.
The most recent 10.07-carat stone was on display at the Hong Kong Jewellery & Gem Fair, which took place from 13 September to 19 September.
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