Tanzanite, a mesmerizing gemstone known for its vivid blue-violet hues, is one of the most captivating additions to the world of colored stones. Discovered in 1967 in the Merelani Hills of Tanzania, it quickly became a beloved gemstone, not only for its beauty but also for its rarity and significance as a December birthstone. This article explores tanzanite’s geological origins, historical significance, gemological properties, and its role in culture and jewelry.
Introduction
Tanzanite, a relatively recent discovery in the gemstone world, has rapidly gained prominence due to its striking color and limited availability. Found exclusively in Tanzania, this gemstone is cherished as the birthstone for December and the gift for the 24th wedding anniversary. Known for its deep blue to violet coloration, tanzanite is a variety of the mineral zoisite, and its unique formation under specific geological conditions makes it a truly one-of-a-kind gemstone.
This article will explore the history and lore surrounding tanzanite, its geological formation and sources, its gemological properties, and its cultural and symbolic significance. Whether you are a gemstone enthusiast, a jewelry buyer, or a student of gemology, this guide provides a comprehensive understanding of tanzanite’s role in the world of birthstones and its enduring appeal.
History and Lore
Tanzanite may be a relatively new gemstone by historical standards, but its impact has been significant. Discovered in the Merelani Hills of northern Tanzania in 1967, tanzanite was initially identified as a form of zoisite. However, its intense blue-violet coloration set it apart from other known varieties of the mineral. The gem was renamed tanzanite in honor of its country of origin and quickly gained international attention.
Tiffany & Co. played a pivotal role in popularizing tanzanite. Recognizing its potential, the renowned jewelry company launched a major advertising campaign in 1968 to promote the gemstone. This marketing effort helped tanzanite become a global sensation, and it was soon adopted as the birthstone for December. Today, tanzanite is also associated with the 24th wedding anniversary, further cementing its place in the world of gemstones.
The gemstone’s name is a tribute to Tanzania, the only country where it is found. The Merelani Hills, located near Mount Kilimanjaro, are the primary source of tanzanite. The area’s unique geological conditions, including the presence of vanadium and specific heat and pressure levels, contribute to the gem’s striking blue and violet hues. These factors make tanzanite one of the rarest gemstones in the world.
Geological Formation and Sources
Tanzanite is a variety of the mineral zoisite, chemically composed of calcium aluminum silicate with vanadium as a trace element. Its formation is a result of specific geological conditions, including the presence of vanadium, heat, and pressure. These conditions are found only in a small region of northern Tanzania, making tanzanite a truly unique gemstone.
The Merelani Hills, located near the border between Tanzania and Kenya, are the only known commercial source of tanzanite. The area is characterized by grass-covered hillsides, scrub brush, and rocky soil. Mining operations in the Merelani Hills are extensive, with mechanized operations digging over 100 meters (300 feet) into the earth to extract the gemstone. The mines are situated in close proximity to Mount Kilimanjaro, whose snow-covered slopes provide a dramatic backdrop to the mining landscape.
Tanzanite deposits have also been found in Pakistan, but the stones from these locations do not exhibit the same vibrant blue-violet coloration as those from Tanzania. In these cases, the stones require heat treatment to enhance their color, but even after treatment, they do not achieve the same intensity as tanzanite from Tanzania.
The rarity of tanzanite is further emphasized by the limited geographic distribution of its formation. The Merelani Hills cover only a few square kilometers, and the gemstone is not found anywhere else on Earth. This exclusivity contributes to tanzanite’s high value and makes it one of the most sought-after gemstones in the world.
Gemological Properties
Tanzanite is known for its striking blue-violet coloration, which is due to the presence of vanadium. This gemstone is a variety of zoisite, and its color can range from deep blue to violet, with the blue hue being the most valuable. The gemstone’s color can also change depending on the angle of light, a phenomenon known as pleochroism. This means that tanzanite can display different colors when viewed from different angles, adding to its allure.
In terms of hardness, tanzanite ranks between 6.5 and 7 on the Mohs scale of mineral hardness. This makes it a relatively durable gemstone, but it is still susceptible to scratching and chipping if not handled with care. Unlike diamond, which is the hardest mineral on the Mohs scale, tanzanite requires special care to maintain its appearance and luster. It is harder than softer gemstones like pearl but still requires gentle handling to avoid damage.
Tanzanite is typically faceted to enhance its brilliance and color. The gemstone’s refractive index is approximately 1.69 to 1.71, which contributes to its sparkle and depth. Tanzanite is also known for its strong luster, which makes it an attractive choice for jewelry. When cut and polished, tanzanite can display a deep, saturated color that is both captivating and unique.
The gemstone’s transparency can vary, but it is generally clear to slightly included. Inclusions are often visible to the naked eye, but they do not detract from the gemstone’s beauty. In fact, some inclusions can add character and individuality to each tanzanite stone.
Tanzanite is also known for its ability to be cut into large stones. This is one of the reasons why it is so popular in the jewelry industry. Large, well-cut tanzanite stones are highly prized and can command high prices in the market.
Symbolism and Metaphysical Beliefs
Tanzanite carries a wealth of symbolism and metaphysical beliefs, making it a popular choice for those seeking both beauty and meaning in their gemstones. As the birthstone for December, tanzanite is associated with transformation, spiritual growth, and emotional healing. It is believed to encourage individuals to embrace change and seek new beginnings, making it a meaningful gift for those going through significant life transitions.
The gemstone is also associated with the zodiac sign of Sagittarius (November 22 to December 21). Sagittarius is a fire sign ruled by the planet Jupiter, and individuals born under this sign are often described as generous, adventurous, and always looking for ways to improve the lives of those around them. Tanzanite is considered the perfect stone for Sagittarians, as it is believed to bring peace and harmony to "lost souls" and help them find their true place and purpose on Earth.
In some cultures, tanzanite is viewed as a bridge between the physical and spiritual worlds, opening pathways for personal insight and awareness. Its deep blue hue has drawn comparisons to the night sky, symbolizing depth and wisdom. The gemstone is also associated with the winter solstice, a time of reflection and renewal. As the days grow shorter and the nights longer, tanzanite serves as a reminder of the light and beauty that can emerge from life’s challenges.
Tanzanite is also believed to enhance communication and promote emotional healing. Many gemstone enthusiasts advocate that it helps individuals let go of negative experiences and embrace a more positive outlook. These properties make tanzanite not just a beautiful adornment but also a powerful source of energy and positivity.
Care and Cleaning
Due to its relatively low hardness on the Mohs scale, tanzanite requires special care to maintain its appearance and luster. While it is harder than softer gemstones like pearl, it is still susceptible to scratching and chipping if not handled with care. To clean tanzanite jewelry, it is best to use a soft cloth and a mild detergent solution. Ultrasonic cleaners and steam cleaners should be avoided, as they can cause damage to the gemstone.
When storing tanzanite jewelry, it is important to keep it separate from harder gemstones to prevent scratches. Tanzanite should be stored in a soft pouch or a lined jewelry box to protect it from contact with other jewelry. Avoid exposing tanzanite to extreme temperatures or direct sunlight for prolonged periods, as this can cause the gemstone to fade or lose its luster.
For those who wear tanzanite jewelry regularly, it is a good idea to have it inspected and cleaned by a professional jeweler periodically. This will help ensure that the gemstone remains in optimal condition and continues to display its captivating beauty for years to come.
Conclusion
Tanzanite is a remarkable gemstone that combines beauty, rarity, and symbolism in a way that few other stones can. As the birthstone for December, it is associated with transformation, spiritual growth, and emotional healing. Its unique geological formation and limited availability make it one of the most sought-after gemstones in the world. Whether worn as a piece of jewelry, given as a gift for a 24th wedding anniversary, or cherished for its metaphysical properties, tanzanite continues to captivate gemstone enthusiasts and jewelry lovers alike.
From its discovery in the Merelani Hills of Tanzania to its rise to international fame, tanzanite has become a symbol of elegance and exclusivity. Its deep blue-violet coloration, combined with its rarity and cultural significance, ensures that it will remain a beloved gemstone for generations to come.