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.
An Examination of the Napoleon Diamond Necklace
Napoléon Bonaparte gave an extraordinary diamond necklace to his empress, Marie-Louise, in 1811.
A Foundation for Grading the Overall Cut Quality of Round Brilliant Cut Diamonds
The GIA diamond cut grading system described here includes the components of brightness, fire, scintillation, polish and symmetry, as well as weight and durability concerns, into a single overall grade for cut quality for standard round brilliants.
Winter 2011 G&G Lab Notes
This section, from the Winter 2011 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Diamonds in Canada
This article chronicles the discovery of primary diamond deposits throughout Canada, whose increasing supply of rough stones will have a growing impact on the world diamond industry.
The “Type” Classification System of Diamonds and Its Importance in Gemmology
Knowledge of type allows gemmologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.
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.
Star of the South: A Historic 128 Ct Diamond
This article presents the first complete gemmological characterisation of the historic 128.48 ct Brazilian diamond known as the Star of the South.
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.
The Impact of Internal Whitish And Reflective Graining on the Clarity Grading of D-To-Z Colour Diamonds at the GIA Laboratory
This article reviews the GIA Laboratory’s history of reporting on certain types of graining which are often the only characteristics present in large, high-clarity, high-colour diamonds.