Gemmological Characterisation of Sapphires from Yogo Gulch, Montana
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
Beryllium Diffusion of Ruby and Sapphire
The heat treatment of corundum involving lattice diffusion of beryllium (Be) at temperatures over 1800°C has become a major issue in the gem trade.
A study of the gems in ciborium from Einsiedeln Abbey
The gemstones that adorn a late-16th-century ciborium from Einsiedeln Abbey in Einsiedeln, Switzerland.
Abstracts; Summer 2009
This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
Ruby and Sapphire from Jegdalek, Afghanistan
This study provides detailed mining and gemmological information on the Jegdalek deposit, in east-central Afghanistan, which is hosted by elongate beds of corundum-bearing marble.
Status of Ruby and Sapphire Mining in the Mogok Stone Tract
This article, based on two recent visits to Mogok, briefly reviews the mining history and geology of this extraordinary locality, and describes the current status of mining and the methods used to recover rubies and sapphires in the Mogok area.
“Ti-Sapphire”: Czochralski-Pulled Synthetic Pink Sapphire from Union Carbide
One of the most interesting of the commercially available Czochralski pulled synthetic corundums is pink “Ti-sapphire.”
The Yogo Sapphire Deposit
Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States.
Rubies and Fancy Sapphires from Vietnam
Gem-quality rubies and pink to purple sapphires are being recovered from the Luc Yen and Quy Chau mining regions of Vietnam.
A Survey of the Gemstone Resources of China
China has identified many deposits with significant potential to produce gemstones; various species are discussed.