Rapaport News




Advanced search
Latest Articles
Rough Markets
Polished Markets

GIA Spots Natural Diamond with CVD Blue Layer

Rare combination of diamond characteristics alerts gemologists to a natural-synthetic hybrid.
May 4, 2017 4:14 AM   By Rapaport News
Print Print Facebook Facebook Twitter Twitter Share Share

The Gemological Institute of America (GIA) has found a natural diamond with a synthetic coating that tints it blue – and has warned that more such hybrids might be on the market.

The 0.33-carat stone, which had been graded fancy blue, had a thin layer of lab-grown diamond on it, created using chemical vapor deposition (CVD), the GIA explained in a lab note this week. It was the GIA’s first such discovery.

Gemologists at the GIA’s New York lab noticed a number of unusual characteristics that gave away the diamond’s synthetic coloring. The stone contained both nitrogen and boron defects — a rare combination. They also found it was a mixed type Ia and IIb diamond, another highly uncommon scenario. Analysis using the DiamondView imaging machine showed the diamond itself had characteristics of a natural stone, but the top layer bore signs of being manmade.

While the GIA had never before found a synthetic overgrowth on a natural diamond with a fancy-color grade, the lab warned that there were probably more cases out there undiscovered.

“Identification of colored diamonds should be performed very carefully by looking for unusual characteristics, such as a straight boundary line associated with an interface plane, and fluorescence zones with sharp edges in DiamondView images,” the GIA said in the note. “Examination of this fancy-colored composite diamond indicated that similar challenges could exist for colorless and near-colorless diamonds.”
Tags: chemical vapor deposition, cvd, fancy-color diamonds, GIA, Natural Diamond, Rapaport News, synthetic coating, Synthetic diamonds, Synthetics
Similar Articles
GGTLLab Creates Tech for Identifying Stolen Stones
Jun 02, 2019
GGTL Laboratories has developed technology that can match a stolen...
De Beers Opening Blockchain to Industry
Lab-Grown Ban Splits Opinion on Facebook
Comments: (0)  Add comment Add Comment
Arrange Comments Last to First

Call Us: 1-702-893-9400
Member License Agreement   RapNet Trading Rules & Code of Conduct    Privacy Policy  
twitter twitter
About Rapaport
Advertise with us