Some of the finest examples of tourmaline today are mined in Southern California near San Diego. Other important sources include Brazil, Sri Lanka, Madagascar and Africa. The state of Maine is an important historical source for tourmaline and still produces small quantities today.
Some tourmalines are heated or irradiated to bring out their best color. Some treated tourmalines may fade if exposed to high heat or very prolonged exposure to intense light.
Tourmaline is a hard gemstone that is resistant to both scratching and breaking, but it should be protected from sharp blows or sudden changes in temperature. Because of the natural internal characteristics found in some tourmalines, especially pinks and reds, ultrasonic cleaning machines should not be used. Tourmaline can be cleaned with most any commercial jewelry cleaner or plain soap and water using a soft brush.
Photo: Robert Weldon, Copyright Professional Jeweler Magazine
Editors Note: This article is © 2002-2014 Jewelers of America Inc.