The Very Deep Origin of the World’s Biggest Diamonds
Explores an exceptional family of diamonds, referred to as “CLIPPIR” (Cullinan-like, Large, Inclusion-Poor, Pure, Irregular and Resorbed), that formed in a super-deep environment.
Colour Grading “D-to-Z” Diamonds at the GIA Laboratory
This article discusses the history and ongoing development of GIA's colour grading system, and explains how its laboratory applies it.
Latest-Generation CVD-Grown Synthetic Diamonds from Apollo Diamond Inc.
High-quality CVD-grown diamonds, comparable in colour and clarity to natural diamonds, can be identified using a combination of gemmological and spectroscopic properties.
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.
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.
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.
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.
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.
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.
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.