Terms of Use


EGL USA is committed to providing clear and accurate analysis results for its customers.
To that end, the lab always delivers cutting edge insight: In-house experts research and refine identification and evaluation techniques; monitor industry trends; and discover and document evolving gemological properties and treatments.

EGL USA raised the bar on modern diamond grading by introducing key features —
firsts” — in industry reporting, such as SI3 recognition and lab-grown diamond identification. The lab similarly improved the accuracy of pearl reports, by introducing x-ray digital imaging to its identification process.

As various types of treated and lab-grown diamonds entered the marketplace, EGL USA pioneered work to further protect and inform consumers. For example, the lab was first to discover and alert the public that high pressure high temperature (HPHT)-treated colored diamonds (Type IIa) and chemical vapor deposition (CVD) lab-grown diamonds were being offered for sale.


Researching Origin of Color in Diamonds

Currently, EGL USA gemologists are refining methods to determine origin of color in various types of diamonds. Extensive comparative characterization data is being compiled based on absorption and photoluminescence spectroscopy, in combination with polarization and fluorescence microscopy.

Researching Diamond Luminescence

EGL USA gemologists are studying the luminescence imaging of diamonds, particularly the appearance of a “fluorescence cage” — a specific intersecting pattern that may help identify diamonds treated via (HPHT) annealing, irradiation, or a combination of both.