China’s National Gemstone Testing Center (NGTC) recently tested a new variety of yellow CVD laboratory-grown diamonds. According to NGTC, they tested stones between 1 – 2 ct, the color of the stones varied from pale yellow to dark brownish yellow, including pure bright yellow. NGTC identified some typical inclusions, including pinpoint dark-color inclusions or dark-color inclusions distributed layer by layer. After production, these lab-grown diamonds are processed in high temperature and high-pressure conditions to remove the brownness hue and enhance their transparency.
A week after the Gemological Institute of America (GIA) announced that its Hong Kong laboratory recently identified an undisclosed chemical vapor deposition (CVD) grown diamond weighing 5.19 carats - the largest ever CVD synthetic diamond ever detected - Tom Moses, the GIA’s executive VP and chief laboratory and research officer explains to Michell Graff of The National Jeweler how lab-grown diamond certificates issued by GIA differ from their natur
US-based diamond grower Scio Diamond Technology Corp. said it has returned to full production following its December shutdown due to what it called a water line break.
In this exclusive article, World Federation of Diamond Bourses (WFDB) President Ernie Blom responds to the story Chaim Even-Zohar, editor of Diamond Intelligence Briefs, published last week about a company offering CVD lab grown (synthetic) diamonds inscribed with the numbers of genuine GIA natural diamond grading certificates on Alibaba, a leading online global wholesale trading platform.
In a startling revelation, industry analyst Chaim Even-Zohar will this week unveil an investigation that shows that CVD lab-grown diamonds are being offered for sale with GIA natural diamond certificates by the giant Chinese online retailer Alibaba which claims to have 400 million users. The diamonds, which come with laser inscriptions and GIA certificates, are offered for sale by an Indian company called the International Trading Corporation.
Scio Diamond Technology Corp, which produces lab-grown Type IIa single-crystal diamonds, has received its 28th U.S. patent for what it describes as its unique process to grow diamonds that are chemically, physically and optically identical to mined diamonds. The newest patent is for Gemstone Production from Chemical Vapor Deposition (CVD) Diamond Plate and was granted on January 5, the firm said in a statement.
The Bharat Diamond Bourse has agreed measures to curb the sale of synthetic diamonds at the bourse, Rapaport News reported. Specific details of the disciplinary action that could be taken against dealers were not provided. The move was approved unanimously at the bourse's annual general meeting, according to several attendees who asked to remain anonymous as they were not authorized to comment on the proceedings. The new rule applies to all synthetics, including CVD. The bourse did not provide further comment.
HRD Antwerp recently examined a 3.09-carat CVD lab-grown diamond. It was the first time that a CVD synthetic diamond of such a size was seen at the lab. CVD (Chemical Vapour Deposition) is a technique where diamonds are grown in a specially developed growing chamber using a carbon rich gas.