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Figure 9. The parcel of rough spinel on the left, reportedly from Tajikistan, contains pieces weighing up to 48.5 g. The seven faceted spinels on the right (9.04–28.16 ct) were fashioned from some of this rough.

Purplish Pink Spinel from Tajikistan: Before and After Cutting

Nicholas Sturman, March 1, 2009

Purplish Pink Spinel from Tajikistan: Before and After Cutting

Beryllium Diffusion of Ruby and Sapphire

John L. Emmett, et al., June 1, 2003

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.

Abstract Header from the 2009 issue of Gems & Gemology

Abstracts; Summer 2009

Brendan M. Laurs, Thomas W. Overton

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

Gary W. Bowersox, Eugene E. Foord, June 1, 2000

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.

The Yogo Sapphire Deposit

Keith A. Mychaluk, March 1, 1995

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

Robert E. Kane, Shane F. McClure, September 1, 1991

Gem-quality rubies and pink to purple sapphires are being recovered from the Luc Yen and Quy Chau mining regions of Vietnam.

Heat Treating the Sapphires of Rock Creek, Montana

John L. Emmett and Troy R. Douthit, September 1, 1993

Renewed interest in large-scale commercial mining of Montana sapphires motivated a detailed study of the heat treatment of sapphire from the Rock Creek deposit.

Sapphires from Changle in Shandong Province, China

Jingfeng Guo, Fuquan Wang, December 1, 1992

The fact that significant amounts of sapphire have been found in situ at Changle makes it unique among sapphire deposits in basaltic terrains around the world.

The Effects of Heat Treatment on Zircon Inclusions in Madagascar Sapphires

Wuyi Wang, Kenneth Scarratt, John L. Emmett, Christopher M. Breeding, and Troy R. Douthit

Zircon inclusions in sapphires from Madagascar were studied to investigate the effects of heat treatment on their gemmological and spectroscopic features.

Tairus Hydrothermal Synthetic Sapphires Doped with Nickel and Chromium

Victor G. Thomas, Rudolf I. Mashkovtsev, September 1, 1997

Researchers from the Tairus joint venture have developed the technology for the hydrothermal growth of gem-quality crystals of synthetic sapphire.

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