Treated-Color Pink-To-Red Diamonds from Lucent Diamonds Inc.
Using a multi-step process, Lucent Diamonds has developed a new treatment process for certain natural diamonds that creates colors from pink-purple through red to orangy brown.
Modeling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Fire, and More about Brilliance
This second major article in a three-dimensional modeling study analyzes fire – the visible extent of light dispersed into spectral colors.
Modeling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Brilliance
A mathematical model which can analyze how appearance factors depend on proportions.
Color Phenomena of Blue Amber
Investigates the presence of fluorescence, rather than iridescence, as the cause of color in blue amber from the Dominican Republic and Indonesia.
Unusual Optical Effect in Blue Sapphire
A bluish violet sapphire shows surprising effects under lab examination.
Sapphire from the Mercaderes-Río Mayo Area, Cauca, Colombia
An important source of gem-quality sapphire and its inclusions is found in Colombia.
An opal featuring a rare six-rayed star is examined in GIA's Bangkok lab.
A History of Diamond Treatments
Modern gemologists and diamantaires are faced with a broad spectrum of color and clarity treatments ranging from the simple to the highly sophisticated.
Abstracts; Summer 2009
This article, from the Summer 2009 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.