A gemstone capable of gathering the "colors of the rainbow" within itself, Tourmaline is undoubtedly one of the finest examples! In 1912, the Jewelers of America first designated Tourmaline as the October birthstone. A century has passed, and Tourmaline is now known by an increasing number of people. Coinciding with October, today GUILD will comprehensively interpret the unique charm of the "Rainbow Gem" for you, covering history, gemological properties, origins, and a selection guide!
History and Legends
The name of Tourmaline is like a microcosm of cultural fusion. Its English name, "Tourmaline", originates from the ancient Sinhalese word "Turmali", meaning "mixed gem", accurately describing the characteristics of Tourmaline having rich colors and a complex composition. In China, Tourmaline has aliases such as "Bi Xi", "Bi Xi", and "Bi Xia Xi". The Qing Dynasty text "Shi Ya" records: "Bi Xia Xi, also known as Bi Xia Pin, also known as Bi Xi; colors of red and green intermixed, or pure green or pure red, crystal clear and lovely," which fully demonstrates the ancients' affection for it.
Regarding the legends of Tourmaline, the most romantic version belongs to ancient Egypt. Ancient Egyptians believed that the growth process of Tourmaline was full of "heliotropism": it sprouted from deep within the crust, always growing towards the sun, moving along the path of the rainbow, and finally absorbing all the colors of the rainbow into the crystal—this is the origin of the title "Rainbow Gem". In ancient Egyptian jewelry culture, Tourmaline was often inlaid on amulets, symbolizing "peace" and "safety". People believed it could transmit the "positive energy" of the rainbow to the wearer.
In China, the popularity of Tourmaline began during the Ming and Qing dynasties, reaching its peak especially in the Qing Dynasty. According to the "Qing Court Archives", Empress Dowager Cixi had a particular fondness for Tourmaline; she not only collected a large amount of Tourmaline jewelry but also used it for palace decoration. The Tourmaline at that time was mostly imported from Brazil. Due to its scarcity and high transportation costs, it once became a "Royal Exclusive Gem".
European Tourmaline culture is closely linked to "scientific discovery". At the end of the 18th century, Dutch physicists discovered that Tourmaline possesses unique "piezoelectricity" (generating an electric charge under pressure) and "pyroelectricity" (becoming electrically charged on the surface when heated, capable of attracting dust). This characteristic meant it was used not only for jewelry but also in early scientific instruments. During the 19th-century Victorian era, Tourmaline became one of the mainstream gemstones for European noble jewelry. Jewelry designers of the time favored pairing red Tourmaline with pearls, creating pieces that combined elegance with vitality, which remain a popular category in the antique jewelry market today.
Gemological Properties
| Col 1 | |
|---|---|
| 碧玺Tourmaline | |
| 化学成分 | 成分复杂的含硼硅酸盐 |
| 晶系与结晶习性 | 三方晶系，常呈柱状，可见晶面纵纹，横断面呈球面三角形 |
| 颜色 | 颜色丰富，常见红色、粉色、绿色、蓝色、黄色或褐色等 |
| 光泽与透明度 | 玻璃光泽，透明 |
| 光性特征 | 一轴晶，负光性 |
| 多色性 | 中等至强的二色性，多色性强弱与宝石体色有关 |
| 折射率与双折射率 | RI=1.624-1.644(+0.011/-0.009)DR=0.018-0.040，常为0.020 |
| 吸收光谱 | 红色、粉红色碧玺在绿光区可见一宽的吸收带，有时可见525nm窄带，451、458nm吸收线。蓝色、绿色碧玺在绿区具498nm强吸收带，蓝区有时可有468nm吸收线 |
| 发光性 | 紫外光下常呈惰性，部分具有红色荧光 |
| 摩氏硬度 | 7-7.5 |
| 密度 | 3.06(+0.20/-0.06)g/cm³ |
| 放大检查 | 常见后刻面棱重影，气液包裹体，管状包裹体，平直或三角形色带或生长纹 |
Origins
Tourmaline origins are distributed across major continents, mainly concentrated in Brazil, the United States, Afghanistan, Africa, and China. As the saying goes, "different soils yield different stones." Tourmaline nurtured by different regional geological conditions varies in color varieties, market recognition, and value.
Brazil is the world's premier Tourmaline origin, producing almost all colors of Tourmaline, renowned for its high volume and complete variety. Among them, the state of Minas Gerais produces red, green, blue, pink, and other colors of Tourmaline; the most prestigious are Rubellite (Red Tourmaline) and Green Tourmaline. Meanwhile, the state of Paraíba shocked the entire gemological community with the discovery of Paraíba Tourmaline in 1989—its blue-green color with a neon glow remains a legend chased by collectors to this day. Regrettably, Brazil's high-quality Tourmaline mine sources, especially the output from the old Paraíba mines, have decreased significantly, directly leading to a continued rise in prices.
The African continent is also an important production area for Tourmaline, renowned for its vivid colors and diverse varieties. For instance, Mozambique produces superior red Tourmaline and bi-color Tourmaline, and a new Paraíba Tourmaline vein was discovered there in 2000; it has now become a main force in market supply. Madagascar is Africa's largest Tourmaline origin, producing Tourmaline in various colors, among which the red Tourmaline is of the best quality. Tanzania is an important origin for Chrome Tourmaline; this Tourmaline presents a vivid emerald green due to the presence of chromium, but the crystals are usually small, and those over 5 carats are already very rare. Tourmaline produced in Nigeria is characterized by bright colors and numerous varieties, and neon blue Paraíba Tourmaline has also been discovered there.
Other important origins include the United States, Afghanistan, China, and others. From Brazil's legendary Paraíba mine to Africa's emerging Mozambique mines, different geological environments have nurtured Tourmaline with unique characteristics. Together, they constitute the magnificent and colorful global landscape of the Tourmaline family, bringing endless surprises to the market.
Selection Guide
Evaluating the value of a Tourmaline requires a comprehensive consideration of multiple dimensions such as color, clarity, cut, and weight. Generally speaking, those with vivid colors, high transparency, excellent cut, and larger size are considered top grade. Among many factors, color is undoubtedly the most important evaluation index, while the quality of the cut directly determines the gemstone's visual effect.
01. Color
Tourmaline's color is the core of its value and the dimension most concerned by the market. To more accurately describe and distinguish the rich colors of Tourmaline, GUILD Gem Laboratories, based on thousands of test data, has established a Tourmaline color grading system. It quantifies and evaluates color from three dimensions: "Hue, Saturation, and Tone," assigning corresponding commercial names to different colors.
Pink-Red Series Tourmaline
Tourmaline appears red to pink due to the presence of manganese, with obvious pleochroism. For the pink-red series of Tourmaline, GUILD has currently introduced commercial names such as Fuchsia Rose, Cherry Blossom Color, Hot Pink, and Lotus Color.
Among them, red Tourmaline with vivid and rich color, carrying a slight orange or purple tone, is often named Rubellite—its name originates from "ruby-like", meaning "like a ruby". Historically, some high-quality Rubellites were indeed often mistaken for rubies. For red Tourmaline meeting the Rubellite standard, GUILD will mark "Natural Rubellite" in the Variety column of the report and assign the commercial name "Fuchsia Rose".
Among pink-red Tourmalines, there are also those with pink as the main tone. Among them, Tourmaline rated as "Cherry Blossom Color" must reach a vivid pink grade; its color is bright and romantic like cherry blossoms, favored by young women. "Hot Pink" Tourmaline similarly needs to reach a vivid pink or vivid purplish pink rating, but with higher saturation, giving a more intense visual feeling. "Lotus Color" Tourmaline possesses both pink and orange simultaneously, like the color of lotus petals, gentle and elegant.
Orange-Yellow Series Tourmaline
The yellow series of Tourmaline covers colors such as medium yellow, orange-yellow, and brownish-yellow. For orange-yellow Tourmaline, GUILD has currently introduced commercial names such as Canary Yellow, Golden Yellow, and Champagne Color.
Tourmaline rated as "Canary Yellow" possesses the purest yellow, with high color saturation and brightness; the yellow is clear and dazzling, like the feathers of a canary in the sunlight. Orange-yellow Tourmaline with high saturation and brightness is rated as "Golden Yellow"; it has a yellow base wrapped in a natural orange tone, blending the two hues into a mellow warm gold texture. "Champagne Color" is an orange with a yellow tone; the color is like champagne, soft and not dazzling.
Blue-Green Tourmaline
The colors of blue-green Tourmaline are very rich, but the chromophores differ. The cause of blue in Tourmaline is related to trace iron ions contained, while the green is related to iron, chromium, and vanadium ions. The chromophores for the "Paraíba" Tourmaline, which stands out with a fluorescent visual effect, are copper and manganese.
For Paraíba Tourmaline, GUILD has introduced the commercial names Neon Blue and Neon Green. For blue-green Tourmaline of different colors, GUILD has introduced commercial names such as Lagoon Color, Indigo Color, Electric Green, Mint Green, and Lemon Color.
"Lagoon Color" is a combination of rich lake green and deep sea blue; it is a blue-green color range applicable to blue-green Tourmaline with appropriate saturation and higher brightness. "Indigo Color" refers to Tourmaline colored by iron, with a main tone of blue; the tone is deep and full of vitality.
Blue, blue-green, green-blue, and green Tourmaline colored by copper and manganese are again called Paraíba Tourmaline. GUILD will mark "Natural Paraiba Tourmaline" on the certificate. Its color is bright with a fluorescent feel; when it meets the corresponding standards, it will be assigned the commercial name "Neon Green" or "Neon Blue".
In green Tourmaline, the color of "Electric Green" Tourmaline is full of a technological feel, like the green code in "The Matrix," dazzlingly bright and particularly tense. "Mint Green" Tourmaline is the fresh variant within green Tourmaline; it has high brightness and low to medium saturation, with a color as refreshing as a mint candy, which can carry a slight blue tone. "Lemon Color" Tourmaline is a color intermixed with yellow and green, like a fresh lemon; it has high brightness and low saturation, bright and moving.
02. Cut
If color is Tourmaline's talent, then cut is the key to awakening its inner brilliance. An excellent cut allows light to refract and reflect perfectly within the gemstone, thus maximizing the display of its color and fire, making the Tourmaline shine from any angle.
In the GUILD Gem Cut Grading System, a comprehensive evaluation is conducted based on the gemstone's proportions, symmetry, and polish performance. Through strict control of these key factors, we ensure that the cut quality of every gemstone meets high standards, providing consumers with a reliable and professional basis for selection.
Conclusion
Having walked through history and legends, traced global origins, and decoded the mysteries of color and cut, do you have a deeper understanding of Tourmaline? If you also wish to acquire a Rainbow Gem of your own, the GUILD Grading Certificate will be your best guide to selecting its quality and value.
