A History of Diamond Treatments
Modern gemmologists and diamantaires are faced with a broad spectrum of colour and clarity treatments ranging from the simple to the highly sophisticated.
Modelling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Fire, and More about Brilliance
This second major article in a three-dimensional modelling study analyses fire – the visible extent of light dispersed into spectral colours.
Modelling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Brilliance
A mathematical model which can analyse how appearance factors depend on proportions.
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.
A Report on the New Watermeyer Split-Facet Diamond Cuts
Introducing a new technique in diamond cutting that virtually eliminates the "bow-tie" effect.
Ruby in Diamond
The first substantiated identification of corundum (var. ruby) occurring as an inclusion in natural diamond is presented.
Abstracts; Summer 2009
This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
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.
“Fluorescence Cage”: Visual Identification of HPHT-Treated Type I Diamonds
HPHT-treated type I diamonds of various colours may exhibit unusually intense fluorescence at the facet edges and junctions.