Tanzanite, the vibrant blue-violet gemstone, stands as a modern marvel in the world of precious stones. Discovered in the late 20th century, it has rapidly ascended to become one of the most celebrated birthstones for December, sharing the month with traditional stones like turquoise, blue topaz, and zircon. Its unique color, rarity, and compelling origin story contribute to its profound appeal. This article delves into the characteristics, history, and significance of tanzanite, exploring its journey from the mines of Tanzania to the hands of jewelry enthusiasts worldwide. We will examine its geological formation, distinctive gemological properties, its role as a symbol of new beginnings, and practical considerations for its care, providing a comprehensive guide for gemstone lovers and prospective buyers.
History and Lore
The history of tanzanite is exceptionally brief, placing it among the youngest of all recognized gemstones. Its story began in 1967 in the Merelani Hills of northern Tanzania, near the base of Mount Kilimanjaro. A Maasai herder is credited with its initial discovery, though the exact circumstances vary in retellings. The gemstone was subsequently identified by a prospector named Manuel d’Souza, who, along with others, began mining the area. The initial name given to the stone was "blue zoisite," a reference to its mineral family. However, the gemstone lacked the marketability and memorability needed for commercial success.
Recognizing the gem's potential, the Tiffany & Co. jewelry house played a pivotal role in its introduction to the global market in 1968. To create a distinct and appealing identity, Tiffany & Co. renamed the gemstone "tanzanite," a direct homage to its exclusive geographic origin. This strategic move, coupled with a massive marketing campaign, successfully positioned tanzanite as a rare and precious gem. The renaming also served to simplify the gem's identity, as "blue zoisite" was considered difficult for consumers to remember and pronounce. This marketing success cemented tanzanite's status as a desirable modern gemstone, and its inclusion as a birthstone for December further solidified its place in the jewelry world.
Geological Formation and Sources
Tanzanite's geological story is as unique as its color. It is a variety of the mineral zoisite, specifically the blue to violet form. The gemstone's formation is attributed to a specific set of geological conditions that occurred approximately 585 million years ago during the Neoproterozoic era. The process involved the metamorphism of a rock called gneiss, which was subjected to intense heat and pressure, causing a recombination of minerals. This event, linked to the formation of the East African Rift Valley, created the unique conditions necessary for tanzanite's creation.
The source of tanzanite is extraordinarily limited. The gemstone is found in a small, four-square-kilometer mining area in the Merelani Hills of Tanzania. This specific location is the only known source of tanzanite in the world. The deposits are located within a geological belt that also yields other minerals like graphite, kyanite, and diopside. Mining operations in this region are complex, involving a mix of small-scale and industrial methods. The limited geographic origin contributes significantly to the gemstone's rarity and value. Due to the finite nature of the deposits, there is ongoing concern about the long-term availability of tanzanite, which enhances its allure and investment potential for collectors and connoisseurs.
Gemological Properties
Tanzanite possesses a distinct set of physical and optical characteristics that define its identity and value. Understanding these properties is crucial for gemologists, jewelers, and consumers alike.
Color: The most celebrated feature of tanzanite is its captivating color. It is typically described as a vivid blue-violet, a hue that is rare in the gemstone world. This coloration is due to the presence of trace amounts of vanadium within its crystal structure. A unique property of tanzanite is its pleochroism. This means that the gemstone exhibits different colors when viewed from different crystal directions. Under various lighting conditions, tanzanite can display shades of blue, violet, and a distinct blue-violet. This dynamic color play is a key identifier and adds to the gemstone's visual complexity and appeal.
Hardness and Durability: On the Mohs scale of mineral hardness, tanzanite registers between 6.5 and 7. This places it in a category of gems that require careful handling. While it is suitable for daily wear in jewelry like rings and earrings, it is softer than many popular gemstones such as sapphire (Mohs 9) and diamond (Mohs 10). This relative softness means tanzanite is susceptible to scratching and abrasion if not properly cared for. It also lacks the cleavage found in some other minerals, but its toughness is moderate, making it less ideal for high-impact jewelry settings without protective settings.
Chemical Composition: Tanzanite is a variety of zoisite, with the chemical formula Ca2Al3(SiO4)3(OH). It belongs to the sorosilicate family of minerals. The distinctive blue-violet color is not part of the mineral's base formula but is caused by trace impurities, primarily vanadium. When tanzanite is heated, it can alter or enhance its color, a process that is commonly used in the gem trade to achieve the most desirable blue-violet hues.
Clarity and Inclusions: Like many gemstones, tanzanite is often found with inclusions, which are internal features that can affect its clarity and transparency. The presence, type, and visibility of inclusions are key factors in determining a tanzanite's quality and value. While some tanzanite can be found with exceptional clarity, it is common for the stone to have some visible inclusions. The gem's clarity is assessed by gemologists, and while there is no universal grading scale like the AAA system used for some other gems, retailers may use their own quality labels for marketing purposes. However, these are not industry-standard and should be understood as marketing tools rather than formal gemological grades.
Cut and Carat: The cut of a tanzanite is critical to maximizing its color and brilliance. Due to its pleochroic nature, cutters must carefully orient the rough stone to present the most desirable color face-up. Common cuts include oval, cushion, pear, and round brilliant, which are chosen to enhance the gem's visual appeal. Tanzanite is available in a wide range of carat weights, from small accent stones to large, statement pieces. Larger stones are rarer and command higher prices per carat, following the typical pricing curve for gemstones.
Market Value and Pricing: The value of tanzanite is influenced by several factors, including color saturation, clarity, cut quality, and carat weight. Its price point is generally more accessible than that of many traditional blue gemstones like sapphire. For instance, tanzanite rings are often noted to be much cheaper than diamond rings of comparable size. The price range for tanzanite jewelry can vary significantly. For example, one source indicates that tanzanite rings from a specific retailer are priced between $150 and $2,000, reflecting the diversity in size, quality, and setting materials.
The following table summarizes key gemological properties of tanzanite based on the provided sources:
| Property | Description |
|---|---|
| Mineral Family | Zoisite (Sorosilicate) |
| Chemical Formula | Ca2Al3(SiO4)3(OH) |
| Color | Blue, violet, blue-violet (pleochroic) |
| Cause of Color | Trace vanadium |
| Mohs Hardness | 6.5 - 7 |
| Primary Source | Merelani Hills, Tanzania (only known source) |
| Birthstone Month | December (modern) |
Symbolism and Metaphysical Beliefs
Tanzanite is imbued with a rich tapestry of symbolic meanings and metaphysical beliefs, many of which stem from its modern discovery and its association with new beginnings. As a gemstone that was introduced to the world in the latter half of the 20th century, it does not have the ancient lore associated with stones like emerald or ruby. However, in the short time since its discovery, it has accumulated a significant body of symbolism.
A primary theme associated with tanzanite is transformation and new beginnings. Its discovery in the 1960s coincides with a period of great social change, and the gemstone itself is a product of a dramatic geological transformation. This has led to its association with personal growth, spiritual awakening, and the ability to navigate major life changes. It is often considered a stone of insight and intuition, believed to enhance one's perception and connection to higher consciousness.
In terms of emotional and interpersonal symbolism, tanzanite is strongly linked to love, loyalty, and harmony. It is said to promote understanding and compassion, making it a popular choice for engagement rings and other jewelry given as a token of commitment. Its calming blue-violet color is thought to have a soothing effect on the mind and emotions, helping to alleviate stress and anxiety. Some belief systems also attribute tanzanite with the power to stimulate the throat and third-eye chakras, enhancing communication and spiritual vision.
It is important to note that these metaphysical beliefs are part of modern crystal healing and spiritual traditions. They are not supported by scientific evidence and should be considered as cultural or personal beliefs rather than proven properties. For many wearers, the symbolism of tanzanite is a personal and meaningful addition to the gem's aesthetic and historical value.
Care and Cleaning
Given its gemological properties, particularly its moderate hardness, tanzanite requires careful handling and maintenance to preserve its beauty and integrity. Proper care is essential, especially for jewelry that is worn regularly, such as rings and bracelets.
Cleaning: The safest method for cleaning tanzanite is with warm water, a mild dish soap, and a soft brush. A soft toothbrush can be used to gently remove any dirt or residue from the setting and the gemstone's surface. It is important to avoid harsh chemicals, acids, or strong alkaline solutions, as these can damage the stone or its setting. Ultrasonic cleaners and steam cleaners are generally not recommended for tanzanite. The vibrations from an ultrasonic cleaner can potentially cause fractures in the stone, especially if it has existing inclusions. Steam cleaners can also be risky due to the potential for thermal shock. After cleaning, the jewelry should be thoroughly rinsed and dried with a soft, lint-free cloth.
Storage and Handling: To prevent scratches, tanzanite jewelry should be stored separately from other jewelry pieces. It is best kept in a soft cloth pouch or in a lined jewelry box with compartments. This prevents the harder gemstones, like diamonds or sapphires, from scratching the tanzanite. When wearing tanzanite rings, it is advisable to remove them during activities that could subject them to impact or abrasion, such as gardening, heavy lifting, or rigorous sports. Due to its relative softness, tanzanite is not the best choice for everyday rings if the wearer has an active lifestyle, though it can be worn daily with proper precautions.
Professional Maintenance: Periodic inspection by a professional jeweler is recommended for any tanzanite jewelry, especially rings. A jeweler can check the security of the stone in its setting, as prongs can wear down over time. If a prong becomes loose, the gemstone could be at risk of falling out. Professional cleaning and polishing can also help maintain the stone's luster, but this should be done by someone experienced with handling tanzanite to avoid any damage.
Conclusion
Tanzanite represents a fascinating convergence of geological rarity, unique beauty, and modern gemological history. Its exclusive origin in a small region of Tanzania, combined with its striking blue-violet color and pleochroic nature, secures its position as a distinctive and coveted gemstone. While it lacks the ancient lore of many traditional birthstones, it has quickly developed its own symbolism, often associated with transformation, new beginnings, and emotional harmony.
As a December birthstone, tanzanite offers a contemporary and elegant alternative to its traditional counterparts. Its accessibility in terms of price, compared to other blue gemstones, makes it an attractive option for a wide range of jewelry, from engagement rings to commemorative pieces. However, its moderate hardness necessitates informed care and mindful wear. For gemstone enthusiasts, jewelry buyers, and students of gemology, tanzanite serves as a compelling case study in the dynamic world of precious stones—a gem whose entire story, from formation to market, has unfolded within a single lifetime, yet has left a permanent mark on the history of jewelry.