Tourmaline is available in more colors than any other gemstone! Green is the most common color, followed by pink to red hues. Blue tourmalines are more expensive varieties, while yellow, orange and purple are rare. Let’s learn more about tourmaline including its use for jewelry.
What Color is Tourmaline?
Tourmaline is a crystalline boron silicate mineral compounded with different elements that cause its different colors. Iron-rich tourmalines are black to bluish-black to deep brown, magnesium-rich varieties are brown to yellow and lithium-rich tourmalines are almost any color: blue, green, red, yellow, pink, etc. Bi-colored and multicolored crystals are also common.
There are four species of tourmaline. The most common is schorl which is exclusively black, never transparent or translucent and found in crystals that are heavily striated. Elbaite is the most well-known and valuable form that occurs in all colors, but is often used to describe green tourmalines. Elbaite is allochromatic, meaning trace amounts of impurities can tint crystals and it can also be strongly pleochroic.
Liddicoatite wasn’t recognized as a separate species until 1977. Prior it was thought to be Elbaite. Its color is usually smoky brown, but also pink, red, green, blue, or rarely white. Dravite, also called brown tourmaline, is the sodium magnesium rich tourmaline endmember.
Tourmaline Color Varieties for All Species
- Achroite – colorless tourmaline
- Rubellite – red tourmaline (color due to iron and manganese)
- Indicolite – blue tourmaline (color due to iron)
- Verdelite – green tourmaline (color due to iron and titanium)
- Siberite – reddish-violet tourmaline
- Watermelon – a pink core with green edges
- Bi-color – two colored tourmaline
- Tri-Color – three colored tourmaline
- Paraiba – neon colored elbaite tourmaline (color due to copper and manganese)
Is Tourmaline Good for Engagement Rings and Jewelry?
Tourmaline ranges from 7 – 7.5 on Mohs scale of hardness, which places it on the upper end of the scale. It’s one of the most widely used gems in any kind of jewelry, including rings since it’s hard enough to take the rigors of daily wear. In addition to October’s birthstone, it’s also the gem of the eighth wedding anniversary. The name comes from the Singhalese words “tura mali,” which translates to “stone with mixed colors.”
You can choose a gem in the color that speaks to you and chances are no one else will have a stone with the exact same color. All colored tourmalines display pleochroism, meaning their color changes when viewed at different angles. Gemstone cutters take this into account so the finished gem brings out its best color. Heat and irradiation are common treatments used to improve the color of tourmaline commonly done after the stone has been cut and polished.
Tourmaline is a pyroelectric mineral, meaning that when warmed it can become electrically charged and attract dust and other lightweight particles. As it cools off it releases a positive charge at one end and a negative one at the other, which causes it to oscillate. This is known as ‘pyro-electricity’ , the ability to generate an electrical potential when they are heated or cooled.