GIA discovers synthetic CVD overgrowth on a natural diamond

A recent discovery at GIA brought to light a synthetic CVD overgrowth on a 0.33 carat natural diamond. For the GIA research team, this is the first such discovery and led to the diamond being graded as a Fancy blue, as per reports. The diamond was found to have nitrogen and boron defects. The research team with the use of DiamondView images discovered other unusual phenomena being discovered including infrared spectrum revealing a mixed type Ia and IIb diamond, yellowish green fluorescence in the face-up view, blue fluorescence in the face-down view and a yellowish green fluorescence zone at the top of the crown with a sharp boundary in the crown facets.

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The GIA researchers noted occurrences which led to understanding that the top layer of the diamond featured characteristics of a synthetic diamond.

The team noted that ‘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. Examination of this fancy-colored composite diamond indicated that similar challenges could exist for colorless and near-colorless diamonds,’ reports say.