EGL USA Discovers “Fluorescence Cage”

EGL USA said it discovered the first visual observational criteria for identifying HPHT stones with certainty. The indicator — the “fluorescence cage” — is a specific luminous intersecting pattern along the cut edges and vertices of facets on particular colored HPHT-treated Ia diamonds with less than strong fluorescence. The visual effect is so distinct, the lab said, it can be seen with a fluorescence microscope.

Early research by Dr. Inga Dobrinets of EGL USA in collaboration with Prof. Alexander Zaitsev of the College of Staten Island/CUNY indicates that the effect results from the movement of optically active impurities, triggered by the HPHT process.

“A significant advantage of the cage-based identification is its comprehensive fidelity and technical simplicity,” explained Dr. Dobrinets. “While the ‘cage effect’ may not appear on all HPHT-treated stones, when it is evident, a conclusive identification can be made on that basis alone.”

EGL USA Director Mitch Jakubovic said the lab plans to put the breakthrough to practical use in the coming months.