The world of birthstones is rich with history, science, and personal significance, offering a unique gem for each day of the year. For individuals born on December 17th, the designated birthstone is the exceptionally rare and visually stunning Tanzanite. This gem, a relative newcomer to the world of fine jewelry, has captivated collectors and enthusiasts with its profound blue-violet hues and a compelling origin story. While Tanzanite stands as the primary birthstone for this specific date, it is part of a larger family of gemstones associated with the month of December, which also includes Turquoise, Zircon, and Blue Topaz. This article provides a detailed exploration of Tanzanite, delving into its geological origins, gemological properties, historical journey, and the symbolic meanings that have made it a cherished stone for those born under the Sagittarius zodiac sign.
The significance of Tanzanite extends beyond its aesthetic appeal; it represents a rare convergence of geological fortune and modern gemological discovery. Found in a single, small region of Tanzania, its limited source contributes to its value and allure. As we explore the multifaceted nature of this gemstone, from its scientific characteristics to the spiritual beliefs it inspires, a comprehensive picture emerges of a jewel that is much more than a simple accessory. It is a symbol of individuality, transformation, and a deep connection to the natural world.
History and Lore: The Modern Gem with an Ancient Feel
Unlike gemstones such as Turquoise or Zircon, which have been prized for millennia, Tanzanite’s history is remarkably brief, yet it has rapidly ascended the ranks of the world's most desired jewels. The gemstone's story began in the late 1960s. According to the provided materials, Tanzanite was discovered in 1967 in the foothills of Mount Kilimanjaro in Tanzania [1, 5]. This discovery marked a pivotal moment in the gemstone industry, introducing a new and mesmerizing option for December-born individuals and gem lovers worldwide [1]. The gem was named by Tiffany & Co., which recognized its potential and introduced it to the market in 1968, quickly promoting it as the most beautiful blue gem to be discovered in the 20th century.
The gem’s rapid rise to prominence is a testament to its unique beauty. Its captivating blue-violet hue drew immediate comparisons to other prized gems, notably the deep blue of sapphires and the regal purples of amethysts [1]. However, Tanzanite possesses a character all its own. Its color, a result of a unique geological accident, is unlike any other gemstone found naturally on Earth.
While its history as a commercial gem is short, the lore surrounding it has developed swiftly. The provided sources do not detail ancient legends, as none exist for this modern stone. Instead, the meaning of Tanzanite is rooted in its modern spiritual interpretations and its story of formation. Its rarity, stemming from its exclusive geographic source, makes it a gem of "rarity and exclusivity" [1]. This limited availability has imbued it with an almost mythical status, a treasure born from a singular place in the natural world.
It is important to note that for those born on December 17th, Tanzanite is not the only officially recognized birthstone. The month of December is unique in offering a variety of official and alternative gems. The traditional birthstone for December is Turquoise, a classic sky-blue gem [3]. Other official December birthstones include Zircon and Blue Topaz [3, 5]. Some sources even list four official stones: Tanzanite, Zircon, Turquoise, and Blue Topaz [5]. This abundance of choice provides December-born individuals with a range of colors and styles, from the soft, earthy charm of Turquoise to the brilliant, diamond-like sparkle of Zircon and the rich, shifting violet-blue of Tanzanite [4, 5]. For those born on December 17th, however, Tanzanite is the specifically assigned gem, a modern classic that speaks to a unique identity [1].
Geological Formation and Sources
The origin of Tanzanite is as singular as its color. It is a variety of the mineral zoisite and owes its captivating blue-violet color to trace amounts of vanadium within its crystal structure. The conditions required for this specific coloration are exceptionally rare, making the gem's existence a geological marvel.
All sources concur that Tanzanite’s only known commercial source is a small, four-square-kilometer mining area in the Merelani Hills of northern Tanzania, situated near the majestic Mount Kilimanjaro [1, 5]. This extremely localized source is a key factor in the gem's rarity and value. Unlike diamonds, which are found in many locations around the world, or sapphires and rubies, which have multiple sources, Tanzanite comes from one single place. This makes it approximately 1,000 times rarer than diamond, a statistic that underscores its preciousness.
The formation of Tanzanite is believed to have occurred around 585 million years ago during a massive tectonic plate shift. This event subjected the zoisite crystals to intense heat and pressure, which, combined with the presence of vanadium, resulted in the unique blue and violet colors. The mining process itself is often challenging, with deposits found in alluvial beds and hard rock, requiring careful extraction.
The gem’s journey from the earth to the market is a testament to its desirability. Since its discovery in 1967, mining operations have been focused in this specific region of Tanzania, with the Merelani mines producing virtually all of the world’s supply of this exceptional gemstone [1]. The geographical limitation not only drives its market value but also adds a layer of mystique and connection to a specific, exotic location on our planet.
Gemological Properties
Understanding the physical and optical characteristics of Tanzanite is essential for appreciating its value and for making informed decisions when purchasing or caring for this gem. Its properties define its durability, brilliance, and overall appearance.
Color: The most defining feature of Tanzanite is its color. It exhibits a mesmerizing range of blue to violet hues. The finest gems display a deep, saturated violet-blue, often with a distinct pleochroic quality, meaning they show different colors (blue, violet, and sometimes reddish) when viewed from different angles. This color-shifting characteristic is a hallmark of the gem. The color is the result of vanadium impurities in the mineral zoisite, which, when subjected to heat during its geological formation, produced the blue and violet colors.
Hardness and Durability: On the Mohs scale of hardness, Tanzanite rates between 6 and 7. This places it in the "moderately durable" category. While it is suitable for most types of jewelry, it is softer than sapphire (Mohs 9) or diamond (Mohs 10). This relative softness means it can be susceptible to scratching if handled carelessly or stored with harder gems. It also lacks "toughness," meaning it can be prone to chipping or breaking if struck with significant force. Therefore, protective settings are recommended for rings and bracelets.
Clarity and Treatment: Tanzanite is typically a "type I" gemstone, meaning it is often "eye-clean," with few visible inclusions. Any inclusions present are usually needles or inclusions characteristic of its host rock. The vast majority of Tanzanite on the market has been heat-treated to achieve its desirable blue color. The natural zoisite crystal is often brownish, but a simple heating process (similar to that used for many sapphires) removes the brownish tones, revealing the beautiful blue and violet hues. This treatment is stable and widely accepted within the gem trade.
Crystal System and Refractive Index: As a member of the zoisite mineral family, Tanzanite has an orthorhombic crystal system. Its refractive index ranges from 1.691 to 1.700, and it exhibits weak to strong trichroism (pleochroism in three colors), which contributes to its dynamic visual appeal.
The following table summarizes the key gemological properties of Tanzanite:
| Property | Description |
|---|---|
| Mineral | Zoisite |
| Chemical Formula | Ca2Al3(SiO4)3(OH) |
| Color | Blue, Violet (pleochroic) |
| Hardness (Mohs Scale) | 6 - 7 |
| Crystal System | Orthorhombic |
| Refractive Index | 1.691 - 1.700 |
| Source | Merelani Hills, Tanzania |
| Treatment | Commonly heat-treated |
Symbolism and Metaphysical Beliefs
While Tanzanite lacks the ancient folklore of Turquoise or Zircon, it has quickly accumulated a rich tapestry of modern metaphysical beliefs and symbolic meanings. For those who ascribe to gemstone lore, Tanzanite is considered a powerful stone for spiritual development and personal transformation.
Based on the provided sources, the symbolism of Tanzanite can be categorized into several key areas:
Spiritual Enlightenment: Tanzanite is strongly associated with spiritual growth and the expansion of consciousness. Its deep, calming blue tones are believed to facilitate a stronger connection with higher realms of consciousness and spiritual guidance. It is considered a gem of choice for individuals on a path of seeking inner wisdom, clarity, and a deeper understanding of their purpose in life [1].
Emotional Balance and Transformation: The vibrant hues of Tanzanite are thought to have a harmonizing effect on the emotions. It is believed to promote a sense of balance, tranquility, and poise, helping individuals navigate emotional turmoil and stress. This connects to its symbolic meaning of "transformation and new beginnings" [4]. For those born on December 17th, it is said to help them navigate the complexities of their emotional landscape with grace [1].
Communication and Expression: In the tradition of crystal healing, colors are often linked to specific chakras, or energy centers in the body. Tanzanite’s association with the throat chakra aligns it with effective communication and self-expression. It is believed to enhance one's ability to articulate thoughts and feelings clearly and honestly, fostering open communication in both personal and professional relationships [1].
These symbolic meanings add a profound layer of personal significance to the gemstone, transforming it from a mere object of beauty into a tool for personal growth and well-being. For the December 17th individual, wearing Tanzanite can be a way to connect with these aspirational qualities of wisdom, balance, and clear expression [1, 4].
Care and Cleaning
Given its gemological properties, particularly its moderate hardness and lack of toughness, proper care is essential to maintain the beauty and integrity of Tanzanite jewelry. Understanding how to clean, store, and wear this gem will ensure it remains a treasured heirloom for years to come.
Cleaning: The safest method for cleaning Tanzanite is with warm, soapy water and a soft brush, such as a baby toothbrush. Gently scrub the gemstone and its setting, paying attention to the area underneath the stone where dirt can accumulate. Rinse thoroughly with clean water to remove all soap residue and pat dry with a soft, lint-free cloth. It is crucial to avoid harsh chemicals, ultrasonic cleaners, and steam cleaners. Chemicals can damage the stone or its setting, while the vibrations from an ultrasonic cleaner can cause existing fractures to worsen, potentially shattering the gem. Steam cleaning is also not recommended due to the potential for thermal shock.
Storage: When not being worn, Tanzanite jewelry should be stored carefully to prevent scratching and chipping. It should be kept in a soft pouch or a separate compartment in a jewelry box, away from harder gems like diamonds, sapphires, and rubies. Storing pieces separately ensures that the softer Tanzanite is not damaged by contact with other jewelry.
Wearing Considerations: Due to its relative softness and brittleness, Tanzanite is best suited for earrings, pendants, and brooches, where it is less likely to be subjected to knocks and impacts. If set in a ring, it should be worn with caution, ideally for special occasions rather than daily wear. A protective setting, such as a bezel or a halo of smaller, harder gemstones, can provide an extra layer of security. As with all fine jewelry, it is wise to remove Tanzanite pieces before engaging in activities like gardening, sports, or heavy household chores.
Conclusion
Tanzanite stands as a remarkable gemstone in the world of birthstones, offering a unique combination of modern discovery, singular origin, and profound visual beauty. For those born on December 17th, it serves as a powerful and personal symbol, a gem whose story is still being written. Its journey from the foothills of Mount Kilimanjaro to the forefront of the global jewelry market is a testament to its captivating allure.
From a gemological perspective, its rich blue-violet color, pleochroic nature, and unique chemical composition make it a fascinating subject of study. While its durability requires mindful care, its brilliance and depth of color are unparalleled. Symbolically, Tanzanite has quickly been embraced for its associations with spiritual enlightenment, emotional balance, and transformative new beginnings, providing a meaningful connection for its wearer.
The existence of other official December birthstones—Turquoise, Zircon, and Blue Topaz—offers a spectrum of choices, each with its own history and character. Yet, for the individual born on December 17th, Tanzanite is the designated gem. It is a stone that reflects the rarity of its own existence, a beautiful and exclusive treasure that perfectly captures the significance of its special day. In wearing Tanzanite, one celebrates not only a birthday but also a connection to a rare and beautiful piece of our planet.