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.
Spectroscopic Evidence of GE POL HPHT-Treated Natural Type IIA Diamonds
Results from spectroscopic analyses of GE POL high-pressure high-temperature (HPHT) annealed nominally type IIa diamonds are presented, and these spectral characteristics are compared with those of untreated diamonds of similar appearance and type.
“Fluorescence Cage”: Visual Identification of HPHT-Treated Type I Diamonds
HPHT-treated type I diamonds of various colors may exhibit unusually intense fluorescence at the facet edges and junctions.
Clues to the Process Used by General Electric to Enhance the GE POL Diamonds
General Electric has developed a variety of high-temperature annealing techniques at different pressures for enhancing the optical properties of polycrystalline synthetic diamond films and single-crystal synthetic diamond.
Synthetic Moissanite: A New Diamond Substitute
Synthetic moissanite is much closer to diamond in overall appearance and heft than any previous diamond imitation; this article reports on how to identify and characterize it.
A Chart for the Separation of Natural and Synthetic Diamonds
Exploration of a chart designed to give jewelers and gemologists a practical guide to identifying synthetic diamonds as they enter the jewelry trade.
An Update on Filled Diamonds: Identification and Durability
This report focuses on recent products from Yehuda/Diascience, Koss & Schecter Diamonds (Genesis II), and Clarity Enhanced Diamond House (a subsidiary of Goldman Oved Diamond Co.).
The Characteristics and Identification of Filled Diamonds
This article reports on the study of six diamonds, both before and after a filling treatment, and the examination of 12 additional filled stones.
GE POL Diamonds: Before and After
This article explores and identifies the changes that type IIa GE POL diamonds experience before and after HPHT annealing.
A New Lasering Technique for Diamond
Several diamonds were treated for the purposes of observation and report with a new laser technique which does not show the typical surface-reaching drill hole.