The gemstone Tourmaline is the alternative birthstone for October as adopted by the American National Association of Jewellers in 1912. It also the stone for the Zodiac sign of Leo, and the accepted gem for the 8th wedding anniversary.

Egyptian legend tells that tourmaline found its famed array of colours when, on its journey up from the earth’s centre, it passed through a rainbow. Because of its colourful occurrences, tourmaline has been confused with other gems throughout history

Somewhere in Brazil in the 1500s, a Spanish conquistador washed the dirt from a green tourmaline crystal and confused the vibrant gem with emerald. His confusion lived on until scientists recognized tourmaline as a distinct mineral species in the 1800s. The confusion about the stone’s identity is even reflected in its name, which comes from toramalli, which means “mixed gems” in Sinhalese (a language of Sri Lanka). It’s a term Dutch merchants applied to the multicoloured, water-worn pebbles that miners found in the gem gravels of Ceylon (now Sri Lanka).

It’s easy to understand why people so easily confuse tourmaline with other gems: Very few gems match tourmaline’s dazzling range of colours. From rich reds to pastel pinks and peach colors, intense emerald greens to vivid yellows and deep blues, the breadth of this gem’s colour 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 colouring.

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 Tiffany 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 colour. There, craftsmen carved the tourmaline into snuff bottles and other pieces to be set in jewellery. 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 tourmaline.

While plenty of tourmaline is mined around the world, it’s rare to find fine gem-quality tourmaline in bright colours. This range of material means that the price of tourmaline can vary almost as much as the colour.