Article Search Results

Show Filters
Showing 55 results for "*"
Fancy Dark brown to Fancy black Marange diamonds
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.

Read More

Recently discovered and legendary diamonds in the blue/gray/violet color range
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.

Read More

Irradiated 1.06 ct brownish orange HPHT synthetic diamond
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.

Read More

Fluorescence image of Aurora Butterfly of Peace
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.

Read More

Rough and faceted natural-color green diamonds.
Natural-Color Green Diamonds: A Beautiful Conundrum

Characterizes diamonds with exceptionally rare natural green color, based on GIA’s extensive database of samples.

Read More

On the left is a 5.26 ct Fancy deep blue heart shape HPHT synthetic diamond. On the right is a 5.27 ct Fancy deep blue emerald cut HPHT synthetic diamonds.
Article
The Latest on Synthetic Diamonds

Dr. James Shigley, GIA distinguished research fellow, is one of the foremost experts in diamonds and their identification. In this presentation recorded at the 2017 JCK Las Vegas show, he shares the latest developments about HPHT and CVD synthetic diamond

Read More

Article
Pyrope Garnet and Montana Sapphires Highlight Winter 2015 G&G

G&G Brief presents an overview of the content of the Winter 2015 issue of Gems & Gemology.

Read More

Nanocut Plasmaetched Diamonds
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.

Read More

5.03 ct Fancy Deep Blue HPHT Synthetic Diamond
Largest Blue HPHT Synthetic Diamond

Analysis of a 5.03 ct HPHT-grown blue synthetic diamond, the largest ever examined by GIA.

Read More

Article
De Beers Reduces Rough Prices – Too Little?

De Beers reduces rough prices at May sight, undisclosed treated diamonds submitted to GIA and Sotheby’s, Christie’s sales break auction records − again.

Read More