Very few gems match tourmaline’s dazzling range of colors. From rich reds to pastel pinks and peach colors, intense emerald greens to vivid yellows and deep blues, the breadth of this gem’s color range is unrivalled. Brazilian discoveries in the 1980s and 1990s heightened tourmaline’s appeal by bringing intense new hues to the marketplace.
People have probably used tourmaline as a gem for centuries, but until the development of modern mineralogy, they identified it as some other stone (ruby, sapphire, emerald, and so forth) based on its coloring.
One of the earliest reports of tourmaline in California was in 1892. In the late 1800s, tourmaline became known as an American gem through the efforts of gemologist George F. Kunz. He wrote about the tourmaline deposits of Maine and California, and praised the stones they produced.
In spite of its American roots, tourmaline’s biggest market at the time was in China. Much of the pink and red tourmaline from San Diego County in California was shipped to China because the Chinese Dowager Empress Tz’u Hsi was especially fond of the color. There, craftsman carved the tourmaline into snuff bottles and other pieces to be set in jewelry, San Diego County’s famed tourmaline mines include the Tourmaline Queen, Tourmaline king, Stewart, Pala Chief, and Himalaya.
The miners became so dependent on Chinese trade that when the Chinese government collapsed in 1912, the US tourmaline trade also collapsed. The Himalaya mine stopped producing large volumes of gemstones. Other mines in San Diego County, like the Stewart Lithia mine at Pala, still produce sporadic supplies of gem-quality tourmaline. The supply of tourmaline began to expand during the first half of the twentieth century, when Brazil yielded some large deposits. Then, beginning in the 1950s, additional finds appeared in countries around the world. Madagascar and Afghanistan have produced fine red and pink tourmalines.
(GIA Gem encyclopedia)