Gem Profile September 7: Tourmaline

by Rose Marion, Wire-Sculpture.com

Tourmaline

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Tourmaline: A Stone of Many Colors

Tourmaline is a gemstone which is typically a schorl (a mineralogist’s word used since before 1400 in Europe to name the black stone). Black tourmaline enjoyed a boost along with jet and other black gems during Queen Victoria’s mourning jewelry influence in the 1800s. Yet while tourmaline is usually black, the most valued gems modern-day are the unusual colors: green, blue, pink, red (often called rubellite), brown, and “watermelon tourmaline,” which is a tourmaline crystal pink on the inside and green on the outside (bi-colored, like ametrine). Some watermelon tourmaline even has a visible white or translucent “rind” between the pink and green layers!

Yellow tourmaline and purple tourmaline is even more unusual than the non-black colors, but has been found in several locations. A recent discover of canary-yellow tourmaline in Malawi is allowing more yellow tourmaline on the market. Tourmaline can be opaque to transparent, so you may see it as a faceted stone but also as a cabochon.

Indicolite (in-dic-uh-lite) is a special word for dark-blue tourmaline, which was also called Brazilian Sapphire. This word, meaning “blue stone,” was originally “indigolite,” a word probably coming from the South America mines. Some gem-sellers would suggest this gem when a high-end customer is looking for an alternative to sapphire, which tanzanite and iolite would also replace nicely. Peacock-blue indicolite, especially with little to no green hues, is easily as more expensive than an equivalent sapphire, because the true blue color is so rare.

Like iolite, tourmaline has dichroic color-changing properties depending on how it is cut. A gemcutter must take care that he cuts the stone the right way, because cutting on the wrong angle will cause the translucent tourmaline to appear cloudy, dark, and even muddy.

The darkest tourmalines, such as turquoise and green tourmalines, can be heated to lighten the colors. Also, the pink and red tourmalines may have irradiation to enliven the colors.

When tourmaline’s not on its own, you can find it included in quartz, creating the stone called tourmalinated quartz, or tourmalated quartz. Like quartz, tourmaline is made of silica, but also a handful of other elements, such as boron, aluminum, iron, sodium, and lithium.

Tourmaline Sources

Gem-quality tourmaline mainly comes from Brazil and Africa – including Tanzania, Kenya, and Madagascar – with some from Sri Lanka, formerly Ceylon, the land that gave tourmaline its name (possibly from 2 words, one meaning “stone that attracts ash”, and the other “more colors.” The bit about attracting ash is related to the fact that some tourmaline can generate electricity when it’s heated and then allowed to cool! (“pyroelectric”)).

Tourmaline has also been found in the United States: Maine and California were significant producers of tourmaline in the 1900s. In fact, in the early 20th century, those two states at opposite ends of the country were the top producers of gem tourmalines! In 1971, Maine named tourmaline its state gemstone, and some Maine locations, including Oxford County, still have mines open to the public where you can mine for tourmaline for a small fee.

Tourmaline is fairly durable, rating a 7-7.5 on Mohs scale, similar to quartz. However, similar to the hollow inclusions in emerald, tourmaline may have fissures that reach the surface of the stone; in this case, most affected stones would be sealed with resin. Keep tourmaline away from harsh chemicals and direct blows to preserve the stone.

Tourmaline in Culture

Pink and green tourmaline were funeral gifts in centuries-old Native American traditions. Tourmaline has been treasured as a gemstone for well over 2,000 years. An Ancient Egyptian legend explains that as tourmaline journeyed to the earth’s surface, it passed over a rainbow, and took on all its colors! Fitting to its color-changing properties, according to the American Gemstone Trade Association (AGTA), “ancient mystics believed tourmaline could encourage artistic intuition.” Some people believe that wearing jewelry made from the darkest black schorl tourmalines can protect oneself from exposure to radiation.

Tourmaline is a birthstone of October, specifically pink tourmaline, along with opal. Pink tourmaline is also a traditional anniversary gift for the 5th year, an alternative to sapphire with sapphire.  It’s also appropriate for the 8th and 38th anniversaries (and if you or your spouse like it, why not more!)

Next Friday’s Gem Profile is on bronzite, a type of enstatite. Have you made wire jewelry with bronzite or enstatite before? Send your enstatite pictures to tips@wire-sculpture.com, and they could be featured!

Resources & Recommended Reading

• Indicolites
• About Maine Tourmaline
• Tourmaline
• Tourmaline on ICGA
• Tourmaline and Anniversaries

Gem Profile by Rose Marion

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2 Comments

1. 

   Bev

   September 7, 2012 at 8:20 am

   Love Watermelon tourmaline, have visited Maine many times and have tried to find an unset slab or slice to incorporate into an original piece. Have not been able to find any, do you have any suggestions? Would prefer it to be from Maine.
2. 

   Barco

   February 18, 2016 at 9:50 am

   Beautifu lV(^_^)V