Article Search Results

Inclusions in Natural, Synthetic and Treated Ruby

Nathan D. Renfro, John I. Koivula, Jonathan Muyal, Shane F. McClure, Kevin Schumacher, and James E. Shigley, January 26, 2018

Provides a visual guide to the internal features of natural, synthetic and treated rubies.

Figure 1. One of GIA’s new LA-ICP-MS corundum calibration standards sets (set number 1); the epoxy disk containing the set is 1.5 inches in diameter. NIST SRM 610 and 612 glass standards are included to account for trace and non-trace elements, such as those found in inclusions, that were not incorporated into the synthetic sapphire crystals grown for standards. Photo by Jennifer Stone-Sundberg.

Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards

Jennifer Stone-Sundberg, Timothy Thomas, Ziyin Sun, Yunbin Guan, Zachary Cole, Randy Equall, and John L. Emmett, January 26, 2018

Presents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.

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.

Rubies and Sapphires from Winza, Central Tanzania

Dietmar Schwarz, et al.

Since late 2007, rubies and sapphires have been mined by hand methods from both eluvial and primary deposits at Winza in central Tanzania.

Gem Localities of the 2000s

James E. Shigley, Brendan M. Laurs, A. J. A. (Bram) Janse, Sheryl Elen, and Dona M. Dirlam

The past decade saw some impressive discoveries of diamonds and coloured stones.

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.

Flux-Induced Fingerprint Patterns in Synthetic Ruby: An Update

K. Schmetzer and F.J. Schupp, March 1, 1994

Some manufacturers are known to have treated Verneuil flame-fusion synthetic rubies by immersion in a flux melt to induce patterns like the “fingerprints” seen in some natural rubies.

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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