Colors of Tourmaline are rare, green, pink and purplish-red gemstones from deposits near the city of Ibadan in Nigeria’s Oyo state. Wonderfully wearable with a colorful brilliance, Tourmaline is a group of related gemstones whose differences in composition result in a plethora of attractive colors.
Hardness 7 - 7.5
Refractive Index 1.624 - 1.644
Relative Density 2.82 - 3.32
Enhancement None
Beauty
One of the world’s most colorful gem varieties, Tourmaline comes in beautiful greens, pinks and purplish-reds (Rubellite) with desirable medium tones that are not too dark or too light. Rubellite is derived from the Latin ‘rubellus’ (reddish) and the Greek ‘lithos’ (stone). While red and pink are technically the same color, Rubellite is distinguished from Pink Tourmaline by its deeper tone (lightness or darkness of a color) and greater saturation (strength of a color). Dependent on expert cutting and an eye-clean clarity, the highest quality clarity grade for colored gemstones, Tourmaline is always challenging for the lapidary due to areas of internal tension inside Tourmaline crystals and its inherent pleochroism (colors and their intensity change when viewed from different angles). Tourmaline is strongly pleochroic or more specifically, it is the most dichroic (two-colored) of all gemstones. This means each Tourmaline crystal has two colors (primary and secondary), whose intensity changes when viewed from different angles. Because of its strong pleochroism, the orientation of Tourmaline during lapidary is extremely important. Every Tourmaline in this collection has been faceted by experienced lapidaries who carefully orientate each crystal to maximize the gem’s colorful brilliance.
While there are 13 mineralogical varieties of Tourmaline, the main variety is Elbaite. Named after the island of its discovery (Elba) in Tuscany, Italy, Elbaite is the backbone of Tourmaline gemstones. A source of minerals during antiquity, Elba is best known as the island of Napoleon’s exile in 1814. Name a color and in all likelihood you’ll find it in Tourmaline. Even pure ‘amethyst’ purples have appeared since the discovery of the Mozambique Paraíba deposit in the Mavuco area. Tourmaline’s different colors are either identified by a color prefix, such as blue-green, green and pink, or a variety name or prefix. These include Bi Color Tourmaline (two or more colors), Canary Tourmaline (intense yellow from the African nations of Malawi and Zambia), Cat’s Eye Tourmaline (chatoyant Tourmaline), Color Change Tourmaline (green to red), Cuprian Tourmaline (non-Paraíba hues, but still colored by copper and manganese), Indicolite (blue), Paraíba Tourmaline (blue to green, colored by copper and manganese), Rubellite (purplish-red), and Watermelon Tourmaline (pink interior, green exterior, just like the fruit). Another prized, but exceedingly rare variety is Chrome Tourmaline, a vivid pure green East African Dravite colored by chromium and vanadium, the same elements that make Emerald and Tsavorite. Last is Schorl (Black Tourmaline), a variety that is naturally abundant and once popular in mourning jewelry, yet now commercially scarce because it is rarely faceted. Nevertheless, interest in both Black Tourmaline and Black Spinel has increased due to the popularity of Black Diamonds.
While some gemstones look better in natural daylight and others in artificial (incandescent) light, a gemstone’s colors should ideally remain beautiful in any light source. Despite this, all Tourmalines are ‘day gems’, meaning they typically look their very best in natural light. The yellow glare of artificial lights will sometimes accentuate gray and brown tones which may otherwise be invisible.
Tourmaline frequently garners the nickname, ‘the chameleon gem’, not only because of its multitude of colors, but also because of its historic propensity to be confused with other gemstones. Tourmaline is derived from the Sinhalese ‘turmali’, which means ‘mixed parcel’ or ‘stone with mixed colors’ and are a group of related minerals whose differences in composition result in a huge variety of colors.
Rarity
Similar to Garnet, Tourmaline is a group of related minerals whose differences in composition result in a plethora of colors. Major sources for Tourmaline include Afghanistan, Brazil, Madagascar, Mozambique and Nigeria.
In the summer of 1998 one of the world’s most significant Tourmaline deposits was unearthed in a farming area about 40 kilometers from the city of Ibadan in Nigeria’s Oyo state near the border with Benin (West Africa) with later deposits located approximately 135 kilometers from Ibadan.
In 1998 a flood of miners rapidly moved into the area and removed over 1,000 kilograms’ of fine Tourmaline. In less than two years the deposit was virtually mined out and despite subsequent discoveries, it remains very difficult to source quality gems in the open market.
The deposit is alluvial (crystals from weathered pegmatites, intrusive igneous rocks composed of interlocking crystals) and are found under a relatively shallow overburden of soil (about two meters). Many of the Tourmaline crystals have a frosted skin resulting from natural abrasion and weathering, but other crystals have sharp terminations indicating that they have not travelled far from their original source.
Enjoying intense competition amongst international buyers, Tourmaline from any locale have significantly increased in price and decreased in availability. Tourmaline remains incredibly scarce, particularly when eye-clean. Rubellite, along with Chrome Tourmaline, Indicolite, and Paraíba Tourmaline, are the rarest and most valuable Tourmaline varieties.
Durability & Care
Tourmaline is a durable gemstone (Mohs’ Hardness: 7 – 7.5) well-suited to everyday wear. Always store Tourmaline carefully to avoid scuffs and scratches. Clean with gentle soap and lukewarm water, scrubbing behind the gem with a very soft toothbrush as necessary. After cleaning, pat dry with a soft towel or chamois cloth.
Map Location
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