Gems and GemologyGems and Gemology
Home
Tuesday, January 6, 2009Printer-Friendly Page
Service Center
Search
My GIA
Back Issue

Winter 1996, Volume 32, Issue 4

Click to Print
An Update on Imperial Topaz from the Capão Mine, Minas Gerais, Brazil
Daniel A. Sauer, Alice S. Keller, and Shane F. McClure


The Capão mine is one of the oldest and most productive fully mechanized Imperial topaz mines in the historic Ouro Preto area of Minas Gerais, Brazil. Bulldozers, water cannons, and dragscrapers are used in two main pits to remove the thick brown overburden for processing to recover topaz crystals in a broad range of sizes and colors. The rarest color is pinkish purple to purple. Heat treatment will turn some brownish yellow or orange Imperial topaz to "peach" or pink. Preliminary testing suggests that there may be a difference in fluorescence between heat-treated and non-heat-treated topaz.



Appears on pages 232-241

Back to Table of Contents

Click Here to Buy This Issue or to Subscribe to Gems & Gemology

Home | About GIA | Ethics Helpline | Education | Laboratory | GIA Reports | Research | Instruments & Books | Alumni Association
Gems & Gemology | Employment at GIA | Careers Available | Newsroom | Publications | Library | Events & Trade Shows | Support GIA | GIA History | How to Buy a Diamond
Contact | Search | Site Map | Help
This page was last updated 08/15/05 09:08 AM
Use of this site signifies your agreement to its terms of use.
©2002 - 2009 Gemological Institute of America Inc.
GIA is a nonprofit 501(c)(3) organization.
All rights reserved.
World Headquarters and Robert Mouawad Campus
5345 Armada Drive, Carlsbad, California 92008
Tel: 760-603-4000