Photoluminescence Mapping of Optical Defects in HPHT Synthetic Diamond
Demonstrates the importance of this method in identifying diamond treatments, based on the analysis of PL maps acquired from a brownish orange HPHT synthetic diamond.
An Introduction to Photoluminescence Spectroscopy for Diamond and Its Applications in Gemology
Presents the underlying physics and methodology of this analytical technique, which has become an essential tool in identifying treated and synthetic diamonds.
Fluorescence Produced by Optical Defects in Diamond: Measurement, Characterization, and Challenges
How variations in UV lamp output can affect observed fluorescence color and intensity.
Cutting Diffraction Gratings to Improve Dispersion (“Fire”) in Diamonds
A new microlithography process developed to create high-resolution diffraction grating patterns on portions of certain facets can improve the dispersion of light and thus the amount of “fire” in a diamond.
Shenzhen: The Frontier of China’s Gem and Jewelry Industry
All jewelry professionals are familiar with the city of Shenzhen, a global jewelry manufacturing center and a leader of China’s fast-growing gem and jewelry industry. Join the GIA team as we tour the city and discover more about its leading jewelry brands.
Observations on GE-Processed Diamonds: A Photographic Record
Observations made at GIA on 858 GE-processed diamonds revealed several interesting features that may be diagnostic of this kind of diamond. Specifically, a significant percentage exhibited a slightly hazy appearance, noticeable internal graining, and other unusual internal features.
Experimental CVD Synthetic Diamonds from LIMHP-CNRS, France
In the last decade, progress in diamond growth by chemical vapor deposition (CVD) has resulted in significant improvement in the quality of synthetic single crystals.
An Updated Chart on the Characteristics of HPHT-Grown Synthetic Diamonds
A new chart, supplementing the one published in the Winter 1995 issue of Gems & Gemology, summarizes the features of both as-grown (“non-modified”) and treated (“modified”) synthetic diamonds currently in the gem market.
A Preliminary Gemological Study of Synthetic Diamond Thin Films
To evaluate possible problems in separating gem materials coated with a synthetic diamond thin film from their uncoated equivalents, we examined one sample of a free-standing, polycrystalline diamond film about one micron (0.001 mm) thick.
Gemstone Durability: Design to Display
A treatise on the design, display, care and repair of fine gemstones.