Tanzanite, the deep bluish-violet gemstone that emerged as a modern marvel in the world of fine jewelry, holds a unique place among December birthstones. Specifically, for those born on December 23, it is the designated birthstone, symbolizing a rare confluence of geological wonder, cultural myth, and market innovation. Discovered in 1967 in Tanzania and officially recognized as a December birthstone in 2002, tanzanite’s story is one of serendipity, scientific intrigue, and commercial success.
This article delves into the multifaceted nature of tanzanite, exploring its geological formation, cultural and symbolic significance, gemological properties, and practical considerations for care and appreciation. Drawing from authoritative sources and historical accounts, the following sections will illuminate why tanzanite is more than just a birthstone—it is a testament to the interplay of nature, human ingenuity, and the enduring allure of gemstones.
History and Lore: From Lightning to Legend
The story of tanzanite begins with a Maasai folktale, a narrative that weaves myth with the natural world. According to this tale, a bolt of lightning struck the foothills of Mount Kilimanjaro, scorching the land and leaving behind a shimmering blue crystal in the ashes. This legend, though poetic, reflects the gemstone’s geological origin and the dramatic forces that shaped it.
The real-life discovery of tanzanite occurred in 1967 when a Maasai tribesman named Jumanne Ngoma stumbled upon a unique bluish-violet gem in the Merelani Hills of northern Tanzania. At first, these stones were mistaken for sapphires. However, upon closer examination, gemologists identified them as a new and distinct mineral—a unique variety of zoisite. The newly discovered gem was initially named "blue zoisite," but this name was quickly deemed unappealing by marketers. With the help of the renowned jewelry house Tiffany & Co., the gem was rebranded as "tanzanite," a name that honored its country of origin and its singular geographic source.
Tanzanite’s journey from a local curiosity to a globally recognized gemstone was significantly influenced by the marketing efforts of Tiffany & Co. The company launched a campaign that emphasized the gem’s exclusivity and beauty, promoting it as the “gem of the 20th century.” This strategic branding not only elevated tanzanite’s status but also highlighted its rarity—tanzanite is found in only one location on Earth: the Merelani Hills of Tanzania. This exclusivity has contributed to its appeal as a birthstone, particularly for those born on December 23.
In 2002, tanzanite was officially designated as one of the December birthstones, joining turquoise, zircon, and blue topaz. This recognition further cemented its place in the world of gemology and jewelry, allowing it to be associated with the symbolic and historical richness of birthstones.
Geological Formation and Sources
Tanzanite is a variety of the mineral zoisite, which is a calcium aluminum silicate. Its chemical formula is Ca₂Al₃(SiO₄)(Si₂O₇)O(OH)₁. The unique blue and violet hues of tanzanite are the result of trace amounts of vanadium within its crystal structure. The coloration is further enhanced through heat treatment, a process that is both common and accepted in the gem trade. This treatment stabilizes the color and makes the gemstone more vibrant, ensuring that it retains its beauty when set in jewelry.
Geologically, tanzanite forms under specific conditions of heat and pressure, typically in metamorphic rock environments. The Merelani Hills, where tanzanite is found, are a region of geological significance. The area was once part of a volcanic system, and the intense heat and pressure associated with this system contributed to the formation of the gemstone. The presence of vanadium, a relatively rare element, in the surrounding rock played a critical role in the development of tanzanite’s characteristic colors.
Mining operations in the Merelani Hills are limited and carefully regulated due to the gemstone’s rarity. The mines are primarily small-scale operations, and the extraction of tanzanite requires skilled labor and specialized techniques. The gemstone is often found in association with other minerals, and it may require careful separation to preserve its integrity. The production of tanzanite is also affected by the natural depletion of the deposit over time, making it a gemstone of increasing value and scarcity.
The geographic exclusivity of tanzanite is one of its most defining characteristics. Unlike many other gemstones, which can be found in multiple locations around the world, tanzanite is found only in Tanzania. This unique origin has contributed to its mystique and has reinforced the idea that tanzanite is a gemstone of extraordinary rarity and significance.
Gemological Properties
Tanzanite is a gemstone that captivates with its deep blue and violet colors, but its beauty is matched by its unique gemological properties. These properties define its suitability for use in jewelry and its value in the gem trade.
Color and Appearance
Tanzanite is known for its striking pleochroism, a property that allows the gemstone to display different colors when viewed from different angles. The most common colors are deep blue, violet, and purplish-red, with the blue and violet hues being the most desirable. The pleochroism of tanzanite is a result of its crystal structure and the way light interacts with the vanadium atoms within the gem. This optical phenomenon adds to the gemstone’s visual appeal and makes it a popular choice for faceted jewelry.
Hardness and Durability
On the Mohs scale of mineral hardness, tanzanite has a rating of 6 to 7. This places it in the category of moderately durable gemstones. While it is harder than many other gemstones, such as opal and turquoise, it is softer than sapphire and ruby. The hardness of tanzanite means that it is suitable for use in jewelry, but it requires careful handling to avoid scratches and abrasions. Tanzanite also has a perfect cleavage, which means that it can be split along certain planes with minimal force. This property makes it more susceptible to chipping or breaking if it is subjected to impact or pressure.
Refractive Index and Luster
The refractive index of tanzanite ranges from 1.690 to 1.700, which is relatively high and contributes to its brilliance and fire. The gemstone has a vitreous (glassy) luster, which enhances its overall appearance and makes it shine when cut and polished. Tanzanite’s refractive properties are further enhanced by its pleochroism, which creates a dynamic interplay of colors as the gem is moved under light.
Carat and Cut
Tanzanite is typically cut into faceted shapes, such as oval, cushion, and emerald cuts, to maximize its color and brilliance. The most valuable tanzanite stones are those that exhibit a deep blue color and are free from inclusions. Inclusions are common in tanzanite and are often visible to the naked eye, but they do not necessarily detract from the gemstone’s beauty. In fact, some inclusions are considered part of the gem’s character and can add to its uniqueness.
The carat weight of tanzanite can vary widely, but larger stones are generally more valuable due to their rarity. Tanzanite is often cut into larger sizes to showcase its color and pleochroism, making it a popular choice for statement jewelry pieces.
Heat Treatment
As mentioned earlier, tanzanite is typically heat-treated to enhance its color. This process involves heating the raw stone to temperatures between 400 and 600 degrees Celsius, which removes any brown or red tones and intensifies the blue and violet hues. The heat treatment is stable and permanent, ensuring that the gemstone retains its color and beauty over time. However, it is important to note that heat-treated tanzanite should be cleaned carefully to avoid exposing it to excessive heat or chemicals, which could potentially affect its color.
Symbolism and Metaphysical Beliefs
Tanzanite is not only admired for its physical beauty but also for the rich symbolism and metaphysical beliefs associated with it. In many cultures, the gemstone is regarded as a symbol of transformation, intuition, and spiritual growth. Its deep blue and violet hues are often linked to themes of wisdom, communication, and emotional healing.
Cultural and Historical Significance
While tanzanite is a relatively modern discovery, its symbolic meanings have quickly gained traction in various cultural and spiritual traditions. The Maasai people of Tanzania, who were the first to encounter tanzanite, have incorporated it into their cultural practices. For them, the gemstone is a symbol of the earth's power and the connection between the physical and spiritual worlds. The Maasai also believe that tanzanite carries the energy of the land and can be used to enhance one’s connection to nature.
In the broader spiritual community, tanzanite is often associated with the throat and third eye chakras. The throat chakra is linked to communication, self-expression, and truth, while the third eye chakra is associated with intuition, insight, and spiritual awareness. Tanzanite is believed to help open and balance these chakras, promoting clearer communication and deeper understanding. This makes it a popular gemstone for those seeking to enhance their spiritual practices or improve their interpersonal relationships.
Metaphysical Properties
Tanzanite is also believed to have several metaphysical properties that make it a valuable tool for healing and personal development. Some of the most commonly cited properties include:
Emotional Healing: Tanzanite is said to help release emotional blockages and promote emotional balance. It is believed to be particularly effective in helping individuals process grief, trauma, and other difficult emotions.
Spiritual Growth: The gemstone is associated with spiritual transformation and is believed to help individuals connect with their higher selves. It is often used in meditation and spiritual rituals to enhance intuition and promote a deeper sense of purpose.
Communication: Tanzanite is thought to enhance communication by encouraging honesty, clarity, and openness. It is believed to help individuals express their thoughts and feelings more effectively, both in personal and professional settings.
Protection: Some sources suggest that tanzanite offers protective energy, shielding the wearer from negative influences and promoting a sense of safety and security.
It is important to note that while these beliefs are widely held in certain spiritual and metaphysical traditions, they are not scientifically validated. The symbolic and metaphysical properties of tanzanite should be considered as part of a broader cultural and spiritual framework rather than as scientifically proven facts.
Care and Cleaning
Given its moderate hardness and perfect cleavage, tanzanite requires careful handling and cleaning to maintain its beauty and durability. Proper care will help ensure that the gemstone remains in excellent condition for years to come.
Cleaning Methods
Tanzanite can be cleaned using mild soapy water and a soft cloth or brush. It is important to avoid harsh chemicals, abrasive materials, or ultrasonic cleaners, as these can damage the gemstone or affect its color. Ultrasonic cleaners, in particular, should be avoided, as the vibrations can cause the gemstone to crack or chip.
When cleaning tanzanite jewelry, it is recommended to soak the piece in a solution of warm water and a mild detergent for a few minutes, then gently scrub it with a soft-bristled brush. After cleaning, the gemstone should be rinsed thoroughly with warm water and dried with a soft, lint-free cloth.
Storage and Handling
To prevent damage, tanzanite should be stored separately from harder gemstones that could scratch its surface. It is best to store the gemstone in a soft pouch or a jewelry box lined with a soft material. This will help protect it from impacts and abrasions.
When handling tanzanite, it is important to be gentle and avoid exposing it to excessive heat or direct sunlight for prolonged periods. While the gemstone is stable after heat treatment, prolonged exposure to high temperatures could potentially affect its color. It is also advisable to remove tanzanite jewelry before engaging in activities that could subject the gemstone to physical stress, such as sports or manual labor.
Professional Cleaning and Maintenance
For more thorough cleaning or for jewelry that requires professional maintenance, it is advisable to consult a qualified jeweler or gemologist. These professionals have the expertise and tools necessary to clean and assess the condition of tanzanite without causing any harm to the gemstone. Regular inspections by a jeweler can also help identify any signs of wear or damage, ensuring that the gemstone remains in optimal condition.
Conclusion
Tanzanite is a gemstone of extraordinary beauty, rarity, and significance. As the December 23 birthstone, it carries with it a rich history of discovery, myth, and cultural symbolism. From its geological formation in the Merelani Hills of Tanzania to its transformation into a globally recognized gemstone through the efforts of Tiffany & Co., tanzanite exemplifies the intersection of nature and human ingenuity.
The gemstone’s unique properties—its deep blue and violet hues, its pleochroism, and its moderate hardness—make it a fascinating subject of study and a valuable addition to any jewelry collection. Whether admired for its physical beauty, its cultural significance, or its metaphysical properties, tanzanite continues to captivate and inspire.
For those born on December 23, tanzanite is more than just a birthstone—it is a symbol of their connection to the natural world and the enduring allure of gemstones. As a gemstone of rarity and exclusivity, tanzanite is a reminder of the wonders of the Earth and the stories that gemstones can tell.