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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

Suite containing over 36 carats of Yogo sapphire

Gemmological Characterisation of Sapphires from Yogo Gulch, Montana

Nathan D. Renfro, Aaron C. Palke, and Richard B. Berg, August 6, 2018

A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.

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.

A study of the gems in ciborium from Einsiedeln Abbey

Stefanos Karampelas, Marie Wörle, Katja Hunger, Hanspeter Lanz, Danilo Bersani, and Susy Gübelin

The gemstones that adorn a late-16th-century ciborium from Einsiedeln Abbey in Einsiedeln, Switzerland.

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.

Status of Ruby and Sapphire Mining in the Mogok Stone Tract

Robert E. Kane and Robert C. Kammerling, September 1, 1992

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

Mary L. Johnson, Meredith E. Mercer, September 1, 1995

One of the most interesting of the commercially available Czochralski pulled synthetic corundums is pink “Ti-sapphire.”

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.

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