Tanzanite stands as a vibrant testament to the modern evolution of birthstone traditions. A gemstone of singular origin and captivating color, it was added to the official birthstone list in 2002, making it one of the most recent additions to the calendar. Its discovery in the mid-20th century and subsequent rise to prominence, driven by its unique pleochroic properties and a strategic marketing campaign, offers a compelling case study in the creation of a modern gemological icon. This article provides a comprehensive examination of Tanzanite, drawing upon established gemological principles and historical records to explore its geological formation, distinctive properties, and its role within the cultural and commercial landscape of birthstone jewelry. We will investigate its journey from a newly discovered mineral to a cherished birthstone, its suitability for various jewelry applications, and the practical considerations for its care and preservation.
History and Lore: A Modern Classic with Ancient Roots
The history of Tanzanite is exceptionally brief when compared to other traditional birthstones like ruby or emerald, which have been revered for millennia. The gemstone was first discovered in the 1960s in the country of Tanzania, from which it derives its name. The mineral itself is a blue variety of the mineral zoisite. The trade name "Tanzanite" was famously coined and popularized by Tiffany & Co., who recognized its potential and introduced it to the global market in 1968. The company’s marketing efforts were instrumental in establishing the gem’s desirability, positioning it as a rare and beautiful stone available from a single source on the planet.
While Tanzanite’s own history is modern, the concept of birthstones has much deeper origins. The practice of associating specific gems with a person’s month of birth can be traced back to eighteenth-century Europe and quickly spread to the United States. This tradition is believed to have ancient precedents, with some sources referencing the Breastplate of Aaron described in the biblical Book of Exodus. This ceremonial garment was adorned with twelve distinct gemstones, each representing one of the twelve tribes of Israel. Over centuries, this concept evolved, and by the early 20th century, the idea of a specific stone for each month gained significant traction.
The formalization of birthstones in the United States occurred in 1912 when the American National Retail Jeweler’s Association, now known as the Jewelers of America, adopted a standardized list. This list was created to provide consistency for jewelers and consumers. For decades, December was represented by three stones: Zircon, Turquoise, and Lapis Lazuli. However, recognizing the growing popularity and commercial importance of Tanzanite, the Jewelers of America updated the list in 2002, officially adding it as a modern birthstone for the month of December. This addition highlights how birthstone lists are not static but can be amended to reflect new discoveries and market trends.
Geological Formation and Sources
Tanzanite’s geological story is as unique as its color. It is found in a very limited geographic area, making it one of the rarest gemstones in the world. According to the provided information, the gem was first discovered in the Merelani district of northern Tanzania, near the base of Mount Kilimanjaro. The deposits are located in a small, four-square-kilometer mining area, which underscores its rarity. The formation of these gem-quality zoisite crystals is linked to a specific geological event. The tectonic plate shift that created the Great Rift Valley also subjected the parent rock to intense heat and pressure, metamorphosing it and allowing for the growth of these unique blue crystals.
The mining process is challenging and often conducted on a small scale by local miners. The rough material is typically found in a variety of colors, from brown and green to the desired blue-violet. The raw crystals are often opaque and require careful sorting and cutting to yield transparent, facetable material. The intense heat of the geological event that formed the crystals is also mimicked in the laboratory. The vast majority of Tanzanite on the market has been heat-treated to achieve its characteristic blue to bluish-purple hue. This heating process is a standard, permanent treatment that removes the unwanted brownish or greenish tints, leaving the pure, vibrant color that consumers desire. The sources note that this treatment is stable and widely accepted in the gem trade.
Gemological Properties
Tanzanite possesses a set of physical and chemical properties that define its beauty and dictate how it should be used in jewelry. Its most celebrated characteristic is its strong pleochroism, an optical feature where a gemstone displays different colors when viewed from different crystallographic directions. The provided sources note that Tanzanite’s color "changes depending upon the angle of viewing," with a dominant blue, violet, and sometimes reddish hue visible from different angles. This dynamic quality gives the stone a captivating depth and complexity.
The following table summarizes the key gemological properties of Tanzanite based on the information provided:
| Property | Details |
|---|---|
| Mineral Species | Zoisite |
| Chemical Formula | Ca₂Al₃(SiO₄)₃(OH) |
| Hardness (Mohs Scale) | 6.5 - 7 |
| Crystal System | Orthorhombic |
| Refractive Index | 1.691 - 1.700 |
| Pleochroism | Strong (blue, violet, reddish) |
| Durability | Fair to Good |
When evaluating Tanzanite for quality, gemologists consider the "4 Cs": color, clarity, cut, and carat weight. Color is the most critical factor. The most valuable stones exhibit a deep, saturated violet-blue color. Lighter stones are generally less valuable. Clarity is also important; as a Type I gemstone, it is typically "eye-clean," meaning it has no visible inclusions to the naked eye. Any visible inclusions, such as fingerprints or silk, can detract from its value. The cut of a Tanzanite is crucial not only for its brilliance but also for showcasing its pleochroism. A skilled cutter will orient the stone to display the most desirable color face-up. Carat weight is the final factor, with larger stones becoming exponentially more valuable per carat.
Durability is a key consideration for any gemstone intended for jewelry. Tanzanite has a hardness of 6.5 to 7 on the Mohs scale. While this is sufficient for most jewelry types, it is softer than gems like sapphire (hardness 9) or diamond (hardness 10). This places it in the "Fair to Poor" category for overall durability in the context of everyday wear, particularly for rings and bracelets. It is susceptible to scratching from harder materials and can be chipped or broken by a sharp blow due to its perfect cleavage in one direction. This makes protective settings essential and reinforces the recommendation to remove Tanzanite jewelry during strenuous activities.
Symbolism and Metaphysical Beliefs
As a relatively new gemstone, Tanzanite lacks the ancient legends and folklore associated with stones like ruby or emerald. However, in the decades since its discovery, a body of symbolic meaning and metaphysical belief has grown around it. Many people who are drawn to the stone's unique energy have attributed various properties to it. According to one of the sources, "Many believe these gems offer protection, healing properties, and spiritual benefits unique to those born in each month." While the specifics of these beliefs are not detailed in the provided materials, the association of gemstones with such properties is a long-standing tradition.
In modern crystal healing and metaphysical circles, Tanzanite is often associated with transformation, spiritual awakening, and higher consciousness. Its connection to the throat and third-eye chakras is frequently cited, with the belief that it can enhance psychic abilities and facilitate communication on a higher, more spiritual level. The stone's dramatic color change is sometimes seen as symbolic of moving between different states of being or perspectives. For individuals born in December, wearing Tanzanite is believed to foster a sense of calm, intuition, and a deeper connection to one's life purpose.
It is important to approach these metaphysical claims with an understanding that they are part of a cultural and spiritual tradition rather than established scientific fact. The provided sources do not offer specific details on these beliefs, but they do acknowledge the broader context of symbolism and lore that has always been intertwined with the world of gemstones. The beauty and rarity of Tanzanite alone are sufficient to make it a meaningful and personal stone for those who choose to wear it.
Practical Considerations: Care, Cleaning, and Jewelry Selection
Given its "Fair to Good" durability rating, proper care is essential to maintain the beauty and longevity of Tanzanite jewelry. Its hardness of 6.5-7 means it can be scratched by everyday items like dust (which contains quartz, hardness 7) and should be stored carefully away from other, harder jewelry pieces. The most significant risk to Tanzanite is its perfect cleavage. A sharp impact along this cleavage plane can cause the stone to split or chip, a risk that is heightened by the often shallow cuts used to maximize the stone's face-up size.
For cleaning, the safest method for Tanzanite is warm water, a small amount of mild dish soap, and a soft brush. It is crucial to avoid ultrasonic cleaners and steam cleaners. The vibrations from an ultrasonic cleaner can cause existing, perhaps invisible, fractures to propagate, leading to breakage. Similarly, the high heat and rapid temperature change from steam cleaning can also damage the stone. After cleaning, it should be rinsed thoroughly and dried with a soft, lint-free cloth.
When selecting Tanzanite for jewelry, its durability profile should guide the choice of setting and piece type. * Rings: While possible, a Tanzanite ring should be worn with care. It is best suited for "dress rings" worn on special occasions rather than as an everyday engagement ring. If used in a ring, a protective setting, such as a bezel or a halo with smaller, harder stones, is highly recommended to shield the Tanzanite from impact. * Pendants and Earrings: These are ideal applications for Tanzanite. As these pieces are less likely to be subjected to knocks and abrasions, the stone's beauty can be enjoyed with minimal risk. A well-constructed pendant setting will provide good support for the stone. * Necklaces and Bracelets: Tanzanite works well in necklaces and bracelets, but caution is advised for bracelets, which are more prone to bumps and scratches. A tennis bracelet style with Tanzanite should have secure settings and be worn thoughtfully.
The popularity of Tanzanite has also made it a popular choice for personalized jewelry. The concept of "Mother’s Rings," which are set with the birthstones of a woman's children, is a cherished tradition. A mother with children born in December could have a ring featuring Tanzanite alongside the birthstones of her other children, creating a unique and meaningful family heirloom. Similarly, as the trend for birthstone engagement rings grows, some couples may choose Tanzanite for its unique color and personal significance, provided they are aware of the durability limitations and are willing to care for it appropriately.
Conclusion
Tanzanite is a remarkable gemstone that encapsulates the dynamic nature of the modern gem and jewelry industry. Its journey from a newly discovered mineral in the 1960s to an officially recognized birthstone in 2002 illustrates the evolving traditions surrounding gemstones. Its singular origin in the Merelani district of Tanzania contributes to its mystique and desirability, while its striking violet-blue color and strong pleochroism make it a standout addition to any jewelry collection. Although it lacks the ancient lore of traditional birthstones, it has quickly developed its own following, valued for its beauty, rarity, and the personal significance it holds for those born in December. While its "Fair to Good" durability rating necessitates careful handling and protective settings, its suitability for pendants, earrings, and special-occasion rings ensures that its captivating beauty can be safely enjoyed for generations to come.