Cubic Zirconia: An Update
An examination of the skull-melting technique used to produce cubic zirconia, first introduced in 1976, as well as the market status of this diamond simulant and information about its production and quality.
Shell Pearl as a Pearl Imitation
Examination of commercially-available "shell pearls" reveals imitation material.
Dyed Bone as a Red Coral Imitation
A specimen presenting as red coral is revealed to be dyed bone.
Amber with Insect-Bearing Filling
Natural amber beads were found to have been filled with plastic and a variety of insects.
Boron Carbide: A New Imitation of Black Diamond
The Gem Testing Laboratory in Jaipur identified a black diamond-like specimen as boron carbide, a ceramic material typically used in nuclear, military, and aerospace applications.
Abstracts; Fall 1991
This article, from the Fall 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.
Abstracts; Summer 1991
From the Summer 1991 issue of Gems & Gemology, a summary of important gemology-related articles published in other journals.
One of these contributors (PG) recently acquired a 3.91 ct drop-shaped cabochon, purchased in India as a Larimar imitation, that consisted of a ceramic material.
Abstracts; Spring 2009
This article, from the Spring 2009 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.
Spinel Submitted as Diamond
It is a rare occurrence when a diamond simulant submitted to a GIA laboratory turns out to be a natural gemstone.