Tanzanite, with its striking blue-violet hues and singular geographic origin, is one of the most captivating and distinctive gemstones in the world of jewelry and gemology. As the birthstone for December, it holds a special place in the hearts of those born during this month and in the broader appreciation of gemstone enthusiasts. This article explores the geological, cultural, and symbolic significance of tanzanite, its historical journey to becoming a December birthstone, and its role in modern jewelry design. Drawing from authoritative sources, we delve into the properties, lore, and care of this extraordinary gemstone.
Introduction
Tanzanite, a variety of the mineral zoisite, is one of the rarest gemstones in the world. Discovered in 1967 in the Merelani Hills of Tanzania, it quickly captured the attention of gemologists and jewelers due to its vibrant coloration and unique optical properties. It was officially designated as a birthstone for December in 2002, joining traditional December stones like turquoise and blue zircon. Known for its enchanting color range—from deep blue to rich violet—tanzanite is a symbol of transformation, creativity, and emotional balance.
This article provides a comprehensive overview of tanzanite, covering its geological formation, historical significance, gemological properties, and its role in December birthstone traditions. We also explore the symbolism and metaphysical beliefs associated with tanzanite, as well as practical advice on caring for tanzanite jewelry. The information presented is derived from a variety of authoritative sources, including industry publications, gemological institutions, and scholarly articles.
History and Lore
Tanzanite is one of the few gemstones discovered in the 20th century, making its history relatively modern compared to many traditional birthstones. It was first identified in the late 1960s in the Merelani Hills of northern Tanzania. The gemstone was not immediately recognized for its potential; it was only after a geologist named Manuel de Sousa discovered the blue-violet zoisite and shared it with a European mineralogist, that its true value began to be understood.
The name tanzanite was derived from the country of its origin, Tanzania, and the gem was introduced to the global market in 1968 by the renowned gem dealer Campbell Bridges. Bridges, along with the renowned jewelry house Tiffany & Co., played a crucial role in popularizing the stone. One of the early marketing slogans for tanzanite was “in Tanzania and Tiffany’s,” highlighting both the gem’s exclusive origin and its rapid rise to fame in the Western jewelry market.
Tanzanite was officially recognized as a birthstone for December in 2002 by the American Gem Trade Association (AGTA) and the Jewelry Industry Council of America (JICA). Its inclusion was based on a combination of factors, including its rarity, aesthetic appeal, and symbolic resonance. As a relatively new birthstone, tanzanite’s adoption marked a shift in the traditional birthstone calendar, reflecting the changing dynamics of the gem and jewelry industries.
The historical significance of tanzanite is further enhanced by its geographical exclusivity. It is found only in Tanzania, a fact that adds to its mystique and scarcity. This geographic limitation is rare in the world of gemstones, making tanzanite a unique and highly valued addition to the December birthstone lineup.
Geological Formation and Sources
Tanzanite is a variety of the mineral zoisite, a calcium aluminum silicate with the chemical formula Ca₂Al₃(SiO₄)(Si₂O₇)O(OH). What sets tanzanite apart from other forms of zoisite is its striking blue-violet coloration, which is the result of trace amounts of vanadium in its crystal structure. This rare combination of geological conditions—specifically, the presence of vanadium and the particular pressure and temperature at which the crystals formed—contributes to tanzanite's vivid hues.
The Merelani Hills in northern Tanzania are the sole known source of tanzanite. The area is part of the Arusha region, a geologically active zone with a history of metamorphic rock formation. The formation of tanzanite is attributed to the unique interplay of metamorphic processes, including regional metamorphism and hydrothermal activity. These processes occurred under high-pressure and high-temperature conditions, which allowed the transformation of the mineral into its gemstone form.
Mining tanzanite is a labor-intensive and environmentally sensitive process. The gem is typically found in broken fragments within the host rock, requiring careful extraction to avoid damaging the delicate crystals. Due to the gemstone’s fragility and its susceptibility to cleavage, the mining process must be handled with precision to ensure the highest quality material is retrieved.
The exclusivity of tanzanite’s source adds to its value and appeal. Unlike diamonds or rubies, which are found in multiple locations around the world, tanzanite is limited to a single region. This geographic constraint makes it one of the rarest gemstones in the world, with estimates suggesting that the known deposits in Tanzania may be depleted within a few decades.
Gemological Properties
Tanzanite is distinguished by its remarkable gemological properties, which include its color, hardness, refractive index, and optical characteristics. These properties contribute to its allure and make it a popular choice for jewelry.
Color
One of the most defining features of tanzanite is its color. The gemstone exhibits a range of hues from deep blue to rich violet, with some specimens displaying a purplish-blue combination. This coloration is due to the presence of vanadium in the crystal structure, which is responsible for the gem’s pleochroism—the ability to display different colors when viewed from different angles. Tanzanite is trichroic, meaning it can show three different colors: blue, violet, and brown. However, in its cut form, the gem is typically oriented to display the most desirable blue-violet tones, with the brown color being excluded.
Hardness
Tanzanite has a hardness of 6 to 6.5 on the Mohs scale. While this is relatively soft compared to gemstones like diamonds (10) or sapphires (9), it is still suitable for use in jewelry. However, due to its moderate hardness and perfect cleavage, tanzanite is more susceptible to damage than harder gemstones. Care must be taken to avoid subjecting it to hard knocks or high-impact settings that could cause chips or fractures.
Refractive Index and Optical Properties
Tanzanite has a refractive index of 1.694 to 1.700, which is relatively high for a silicate mineral. This high refractive index contributes to its brilliance and fire, making it an attractive gemstone. The gem also exhibits a moderate dispersion, which means it can display a slight amount of fire (rainbow-like flashes) when cut and polished.
Tanzanite is usually transparent to translucent and can vary in clarity. High-quality tanzanite is typically clean and free of inclusions, although some may contain small mineral inclusions or fractures. The clarity of tanzanite is an important factor in its overall value, with cleaner stones commanding higher prices.
Cut and Carat
Tanzanite is typically cut in shapes that maximize its color and brilliance. The most common cuts include the cushion, oval, and emerald cuts. These cuts help to enhance the gem’s color and reduce the visibility of any inclusions or fractures. Tanzanite is available in a range of carat sizes, with most jewelry pieces featuring stones between 1 and 5 carats. Larger stones are rare and highly valued.
Symbolism and Metaphysical Beliefs
Tanzanite is not only valued for its physical beauty but also for its symbolic and metaphysical significance. In modern gemstone lore, tanzanite is associated with transformation, emotional healing, and spiritual awakening. It is often described as a stone of intuition and communication, helping to bridge the gap between the heart and mind.
One of the key metaphysical properties attributed to tanzanite is its ability to promote emotional balance and inner peace. It is believed to help individuals release past traumas and negative emotions, allowing for personal growth and self-discovery. This makes it a popular choice for those undergoing significant life changes or seeking emotional clarity.
Tanzanite is also associated with the throat chakra, which is linked to communication and self-expression. It is thought to enhance one’s ability to express thoughts and feelings clearly, making it a helpful stone for public speakers, writers, and those in need of confidence in social interactions.
In some traditions, tanzanite is believed to have a calming effect on the mind and body. It is used in meditation to promote relaxation and mental clarity. Some practitioners use tanzanite to aid in dream recall and to enhance spiritual insight.
While these metaphysical beliefs are not universally accepted in the scientific community, they reflect the cultural and symbolic significance of tanzanite. The gemstone’s connection to transformation and emotional healing resonates with many people, adding to its enduring appeal.
Care and Cleaning
Due to its moderate hardness and perfect cleavage, tanzanite requires careful handling and cleaning to maintain its beauty and integrity. Proper care ensures that the gemstone remains in excellent condition for years to come.
Cleaning
Tanzanite can be cleaned using warm, soapy water and a soft brush. Ultrasonic cleaners should be used with caution, as they may cause damage if the gem has any inclusions or fractures. Steam cleaners are generally not recommended for tanzanite, as the heat can cause the gem to crack.
When cleaning tanzanite jewelry, it is best to remove the gemstone from the setting if possible. If the gem is set in a ring or pendant, avoid using harsh chemicals or abrasive materials, as these can scratch the surface or damage the setting.
Storage
Tanzanite should be stored separately from harder gemstones to prevent scratches. It is best to keep it in a soft pouch or a lined jewelry box. Avoid exposing tanzanite to extreme temperatures or direct sunlight for prolonged periods, as this can cause fading or damage to the gemstone.
Maintenance
Regular inspections of tanzanite jewelry are recommended to check for loose settings or signs of wear. If any damage is noticed, it should be addressed promptly by a professional jeweler to prevent further issues. Tanzanite is particularly susceptible to damage from hard knocks, so it is important to avoid subjecting it to high-impact activities.
Conclusion
Tanzanite is a rare and extraordinary gemstone that has captivated the world since its discovery in the 1960s. As the birthstone for December, it symbolizes transformation, emotional balance, and spiritual growth. Its unique coloration, geological rarity, and cultural significance make it a cherished gemstone for December babies and a meaningful choice for jewelry lovers.
From its geological origins in the Merelani Hills of Tanzania to its official designation as a December birthstone in 2002, tanzanite has come to represent the beauty and complexity of the natural world. Its vibrant hues, trichroic nature, and metaphysical properties contribute to its enduring appeal in both the gemological and spiritual communities.
While tanzanite may not have the centuries-old history of traditional birthstones like garnet or emerald, its modern significance and growing popularity underscore its importance in contemporary gemstone culture. As a symbol of transformation and emotional clarity, tanzanite continues to inspire and enchant those who wear it.
For those born in December, tanzanite offers a meaningful connection to their birth month, combining aesthetic beauty with deep symbolic meaning. Whether worn as a piece of jewelry or used in meditation and healing practices, tanzanite remains a powerful and captivating gemstone that continues to inspire wonder and admiration.