Black Diamonds from Marange (Zimbabwe): A Result of Natural Irradiation and Graphite Inclusions
Characterizes a suite of 40 natural brown to black diamonds from this deposit so that they can be distinguished from suspected treated black diamonds.
An Early Byzantine Engraved Almandine from the Garibpet Deposit, Telangana State, India: Evidence for Garnet Trade Along the Ancient Maritime Silk Road
Analyzes the chemical composition and inclusion characteristics of this ancient artifact.
Natural-Color Blue, Gray, and Violet Diamonds: Allure of the Deep
Summarizes data collected on more than 15,000 natural blue/gray/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this color range.
Aquamarine, Maxixe-Type Beryl, and Hydrothermal Synthetic Blue Beryl: Analysis and Identification
Aquamarine, Maxixe-type (irradiated) beryl, and two types of hydrothermally grown synthetic blue beryl currently available in the marketplace were investigated by various gemological methods.
Large Faceted Afghanite
A report on the largest facet-grade afghanite seen in the GIA gem identification department.
A Repaired Diamond
A marquise-cut diamond is found to have been broken and reassembled with an unknown adhesive.
Observations on HPHT-Grown Synthetic Diamonds: A Review
Summarizes statistical data and distinctive features of several thousand gem-quality HPHT synthetic diamonds examined by GIA from 2007 through 2016.
Photoluminescence Mapping of Optical Defects in HPHT Synthetic Diamond
Demonstrates the importance of this method in identifying diamond treatments, based on the analysis of PL maps acquired from a brownish orange HPHT synthetic diamond.
Observations on CVD-Grown Synthetic Diamonds: A Review
Explores statistical data and defining characteristics of gem-quality CVD synthetic diamonds examined by GIA since 2003.
An Introduction to Photoluminescence Spectroscopy for Diamond and Its Applications in Gemology
Presents the underlying physics and methodology of this analytical technique, which has become an essential tool in identifying treated and synthetic diamonds.