London Blue Topaz is a gemstone of remarkable depth and clarity, renowned for its captivating oceanic blue hue. As the primary birthstone for the month of December, this variety of topaz is celebrated for its rich color, which ranges from a deep, saturated blue to a vivid, electric blue with greenish undertones. Its status as a December birthstone is well-established, making it a popular choice for jewelry that carries personal significance. The gemstone’s appeal lies in its combination of beauty, durability, and relative affordability, which has contributed to its widespread popularity in modern jewelry markets. This article explores the origins, properties, cultural significance, and care of London Blue Topaz, drawing exclusively from authoritative sources to provide a comprehensive overview for gemstone enthusiasts and jewelry connoisseurs.
History and Lore
The history of topaz is ancient, though the specific variety known as London Blue Topaz is a more modern designation. The term "topaz" is believed to derive from the Sanskrit word tapas, meaning "fire," or from the Greek Topazos, the name of an island in the Red Sea. Historically, topaz was often confused with other yellow and brown gemstones, and its true identity was not always clear. The deep blue variety we know today as London Blue Topaz is the result of specific treatments applied to colorless or pale blue topaz crystals. This process, which involves irradiation and heat treatment, enhances the stone's natural color to achieve its signature deep blue. While the exact origin of the "London Blue" moniker is not detailed in the provided sources, it is widely recognized in the gem trade as the darkest and most valuable grade of blue topaz.
The gemstone's association with December is part of a long-standing tradition of birthstone assignments. The modern list of birthstones, which includes London Blue Topaz for December, was formalized in 1912 by the National Association of Jewelers (now Jewelers of America). This list was updated in 1952 and again in 2002 to include additional stones, but London Blue Topaz remains a cornerstone of December's birthstone options. Its deep blue color is often linked to the winter month, evoking images of clear, cold skies and deep ocean waters, making it a fitting symbol for those born in the final month of the year.
Geological Formation and Sources
Topaz is a silicate mineral with the chemical formula Al₂SiO₄(F,OH)₂. It forms in the cavities of igneous rocks, particularly in pegmatites and rhyolites, where fluorine-rich vapors and fluids interact with aluminum and silicon. The gemstone's crystals can grow to impressive sizes, with some specimens weighing hundreds of carats. While topaz is found in many locations worldwide, the specific sources for the colorless or pale blue topaz that is subsequently treated to become London Blue Topaz are often from Brazil, Nigeria, and Sri Lanka. These regions are known for producing large, clean crystals that are ideal for treatment.
The transformation of raw topaz into London Blue Topaz involves a controlled process of irradiation and heat. First, the stone is exposed to electron beam or gamma radiation, which creates color centers within the crystal lattice. This initial treatment often produces a brownish or greenish hue. Subsequent heating is then applied to stabilize the color and shift it to the desired deep blue shade. This treatment is permanent and stable under normal conditions, making London Blue Topaz a durable and reliable gemstone for jewelry. The process is widely accepted in the gemological community, and treated stones must be disclosed according to industry standards.
Gemological Properties
London Blue Topaz is prized for its excellent gemological characteristics, which make it suitable for a wide range of jewelry applications. The following table summarizes its key properties, based on standard gemological data.
| Property | Description |
|---|---|
| Chemical Formula | Al₂SiO₄(F,OH)₂ |
| Crystal System | Orthorhombic |
| Hardness (Mohs Scale) | 8 |
| Refractive Index | 1.609 - 1.629 |
| Specific Gravity | 3.49 - 3.57 |
| Cleavage | Perfect in one direction |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Color | Deep, saturated blue (treated) |
The hardness of 8 on the Mohs scale makes London Blue Topaz relatively resistant to scratching, though it is not as hard as sapphire or diamond. Its perfect cleavage in one direction means that it can be split along a specific plane if struck with sufficient force, so it requires careful handling during cutting and setting. The refractive index and specific gravity are within the typical range for topaz, allowing gemologists to identify it using standard tools. The color of London Blue Topaz is its defining feature; it is a deep, vivid blue that is often more saturated than other blue topaz varieties like Swiss Blue or Sky Blue. This color is a result of the treatment process, as natural blue topaz is exceedingly rare and typically pale in color.
Symbolism and Metaphysical Beliefs
Throughout history, topaz has been associated with various symbolic meanings and metaphysical properties. In ancient times, it was believed to possess healing powers and was used as a protective talisman. The Romans associated topaz with Jupiter, the king of the gods, and believed it could enhance vision and ward off evil spirits. In medieval Europe, it was thought to break curses and ensure long life. The deep blue color of London Blue Topaz has led to its association with tranquility, clarity, and communication. It is often linked to the throat chakra in alternative healing practices, believed to aid in clear expression and honest dialogue.
In modern metaphysical circles, London Blue Topaz is considered a stone of calm and wisdom. It is said to promote a sense of peace, reduce stress, and encourage a positive outlook. Its deep blue hue is reminiscent of the ocean and the sky, elements that are universally connected to vastness and serenity. For those born in December, wearing London Blue Topaz is thought to harness the stone's energy to bring balance and emotional stability. While these beliefs are not scientifically proven, they contribute to the gemstone's enduring appeal as a meaningful and personal piece of jewelry.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of London Blue Topaz jewelry. Due to its hardness of 8, it is durable enough for everyday wear but should be protected from sharp blows and extreme temperature changes, which could potentially cause damage. The stone's perfect cleavage means it can be vulnerable to impact, so it is advisable to remove jewelry containing London Blue Topaz during activities that could subject it to physical stress, such as heavy lifting or sports.
Cleaning London Blue Topaz is straightforward. It can be safely cleaned using warm water, a mild dish soap, and a soft brush. Avoid using harsh chemicals, such as bleach or ammonia, as they may damage the stone or its setting. Ultrasonic cleaners are generally safe for untreated topaz, but caution is advised for treated stones; it is best to consult with a professional jeweler before using such devices. Steam cleaning is not recommended, as the heat could potentially alter the stone's color or cause internal stress. Storing London Blue Topaz jewelry separately from other pieces will prevent scratching, as it can be scratched by harder materials like diamonds or sapphires.
Conclusion
London Blue Topaz stands as a gemstone of both beauty and resilience, offering a deep, captivating blue that makes it a quintessential birthstone for December. Its journey from a colorless mineral to a vivid blue gem involves precise treatment processes that are now standard in the industry, resulting in a stone that is both accessible and striking. The gemological properties of London Blue Topaz, including its notable hardness and clarity, make it a practical choice for fine jewelry, while its symbolic associations with calm and clarity add a layer of personal meaning for the wearer. Whether chosen for its aesthetic appeal, its birthstone significance, or its perceived metaphysical properties, London Blue Topaz remains a celebrated and enduring choice in the world of gemstones.