Tourmaline, a captivating gemstone boasting an unparalleled range of colors, serves as one of the recognized birthstones for October. While historically, opal held sole claim to this designation, tourmaline was officially added as a second birthstone in 1812, acknowledging its growing popularity and unique qualities. The name itself, derived from the Sinhalese word toramalli, meaning “stone with mixed colors,” hints at the gem’s remarkable polychromism. This article will delve into the history, geological origins, gemological properties, and symbolism of tourmaline, providing a comprehensive overview of this fascinating October birthstone.
History and Lore
The story of tourmaline’s recognition is one of mistaken identity. As early as the 1500s, Spanish conquistadors encountered vibrant green tourmaline crystals in Brazil, initially believing them to be emeralds. This confusion persisted for centuries, only being resolved in the 1800s when scientists definitively classified tourmaline as a distinct mineral species. Even the gem’s name reflects this historical ambiguity, as Dutch merchants applied the term toramalli to the multicolored pebbles found in Sri Lankan gem gravels.
A particularly notable example of this misidentification is the “Caesar’s Ruby” within the Russian crown jewels, which is, in fact, a red tourmaline, known as rubellite. Throughout history, tourmaline has been valued for its beauty and perceived mystical properties. Ancient mystics believed the gemstone could inspire artistic expression, attributing this to its diverse color palette capable of mirroring any mood.
Geological Formation and Sources
Tourmaline is not a single mineral but a group of closely related boron silicate minerals with varying chemical compositions. This complex composition is responsible for the gem’s extraordinary range of colors. The formation of tourmaline typically occurs in granitic pegmatites, metamorphic rocks, and hydrothermal veins. These geological environments provide the necessary elements – boron, aluminum, silicon, and various trace elements – for tourmaline crystallization.
Currently, Brazil remains the most significant source of tourmaline, though the gem is also mined in Afghanistan, Pakistan, Kenya, Madagascar, and Mozambique. Within the United States, California and Maine are historically important producers of fine tourmaline specimens. The specific trace elements present during formation dictate the resulting color, leading to a wide array of varieties.
Varieties of Tourmaline
The diversity of tourmaline is reflected in the numerous trade names assigned to its color variations. Some of the most well-known include:
- Rubellite: Encompassing shades of pink, red, purplish-red, orangy-red, and brownish-red. Debate exists within the trade regarding whether all pink tourmaline qualifies as rubellite.
- Indicolite: Characterized by dark violetish-blue, blue, or greenish-blue hues.
- Chrome Tourmaline: Displaying a vibrant emerald green color.
- Paraíba Tourmaline: Renowned for its neon green and blue-to-violet shades, caused by trace amounts of copper.
- Schorl: The most common variety, accounting for approximately 95% of all tourmaline, and ranging in color from deep brown to bluish-black due to its high iron content. While abundant, much of this variety is not of gemstone quality.
Beyond these, tourmaline can also be found in a spectrum of other colors, including yellow, orange, and even colorless forms. Some crystals exhibit multiple colors within a single stone, further adding to the gem’s allure.
Gemological Properties
Tourmaline generally registers between 7 to 7.5 on the Mohs scale of hardness, making it suitable for everyday wear. The gem is typically stable and resistant to light and most chemicals, though it can be damaged by excessive heat.
Here's a table summarizing key gemological properties:
| Property | Value |
|---|---|
| Hardness (Mohs) | 7 - 7.5 |
| Chemical Formula | Complex Boron Silicate |
| Crystal System | Trigonal |
| Luster | Vitreous |
| Fracture | Conchoidal |
Tourmaline’s chemical complexity means there isn’t a single, definitive chemical formula. The general formula is (Na,Ca)(Al,Li,Mg)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH)4. The varying proportions of these elements contribute to the wide range of colors and properties observed in different tourmaline varieties.
Symbolism and Metaphysical Beliefs
Throughout history, tourmaline has been associated with various symbolic meanings. Ancient mystics believed the gemstone could inspire artistic expression, reflecting its diverse color palette. More broadly, tourmaline has been considered a stone of protection, promoting emotional stability and positive energy. Black tourmaline, or schorl, is particularly valued for its grounding properties and ability to shield against negative influences. While these beliefs are not scientifically substantiated, they continue to resonate with many who appreciate the gem’s aesthetic and perceived energetic qualities.
Care and Cleaning
Maintaining the beauty of tourmaline jewelry is relatively straightforward. The gem is best cleaned with warm, soapy water and a soft brush. Ultrasonic and steam cleaners are not recommended, as they may cause damage. Prolonged exposure to water should be avoided, particularly for tourmaline doublets or triplets, where water can weaken the adhesive bonding the layers. Tourmaline should be stored separately from harder gemstones, such as diamonds, rubies, and sapphires, to prevent scratching.
Conclusion
Tourmaline stands as a testament to the beauty and complexity of the natural world. From its intriguing history of mistaken identity to its dazzling array of colors and varied geological origins, this October birthstone offers a captivating subject for study and appreciation. Its durability, combined with its aesthetic appeal and symbolic significance, ensures that tourmaline will continue to be cherished by gemstone enthusiasts and jewelry lovers for generations to come.