Tanzanite, a mesmerizing blue-violet gemstone, is the birthstone for December and one of the most captivating discoveries in the world of colored stones. Discovered in 1967 in the Merelani Hills of Tanzania, this gemstone is not only rare but also carries a rich tapestry of cultural, spiritual, and geological significance. Known for its deep, saturated colors and its unique geological origin, tanzanite has quickly become a symbol of transformation, spiritual growth, and renewal—making it a cherished gem for December birthdays and other meaningful milestones.
This article delves into the fascinating world of tanzanite, exploring its origins, geological properties, cultural symbolism, and the care required to preserve its beauty. As a relatively new gemstone with a dramatic rise to prominence, tanzanite offers a compelling story of discovery and appreciation.
History and Lore
Tanzanite's history is as extraordinary as its appearance. The gemstone was first discovered in 1967 by a local Maasai herder near the Merelani Hills in northern Tanzania, close to the base of Mount Kilimanjaro. The stone was initially identified as a variety of zoisite, a mineral known for its green color. However, the blue-violet hue of the newly discovered stones was unlike anything previously seen in the world of gemology.
The discovery was brought to the attention of Manuel de Souza, a Portuguese trader who recognized the stone's potential. He then presented the gem to the famous jewelry company Tiffany & Co., which played a pivotal role in promoting and popularizing tanzanite. In 1968, Tiffany launched an aggressive advertising campaign that highlighted the gemstone's beauty and its exclusive origin in Tanzania. The company also suggested the name "tanzanite" to honor the country where it was found.
Tanzanite's rise to fame was swift. By the early 1970s, it had become a highly sought-after gemstone, not only as a birthstone for December but also as a symbol of luxury and rarity. In 2002, tanzanite was officially added to the list of birthstones for December, joining the ranks of turquoise and zircon. This addition marked the first time in nearly a century that a new gemstone had been included in the official birthstone list.
The cultural and spiritual significance of tanzanite has also grown alongside its popularity. In many cultures, the deep blue and violet tones of the gemstone are associated with wisdom, depth, and transformation. It is believed to promote emotional healing, enhance communication, and encourage the release of negative experiences. Some also regard tanzanite as a stone that connects the physical and spiritual worlds, making it a powerful tool for personal insight and spiritual growth.
Geological Formation and Sources
Tanzanite is a form of the mineral zoisite, which has the chemical formula Ca₂Al₃(SiO₄)(Si₂O₇)O(OH). What distinguishes tanzanite from other varieties of zoisite is its striking blue-violet color, which is the result of trace amounts of vanadium. This coloration is only possible under specific geological conditions, which is why tanzanite is found almost exclusively in one location on Earth: the Merelani Hills of northern Tanzania.
The Merelani Hills are located near the town of Arusha, in the shadow of Mount Kilimanjaro, Africa's highest peak. The region is characterized by a unique geological environment that includes metamorphic rocks formed under high pressure and temperature. These conditions, combined with the presence of vanadium, create the perfect environment for tanzanite to form.
Tanzanite is mined from open-pit and underground mines in the Merelani Hills, with the most significant deposits found at depths exceeding 100 meters (over 300 feet). The mining operations are labor-intensive, involving thousands of workers who manually excavate the gemstone from the earth. The rough stones often appear reddish or brownish in their natural state, but they undergo a heat treatment to reveal their characteristic blue-violet color.
The rarity of tanzanite is a major factor in its value. Unlike diamonds or sapphires, which are found in multiple locations around the world, tanzanite is limited to a small area in Tanzania. In fact, some estimates suggest that tanzanite is thousands of times rarer than diamonds. This exclusivity has contributed to its desirability in the gemstone market.
Another factor that adds to tanzanite's uniqueness is the limited time it will remain in the Earth's crust. Geologists estimate that tanzanite may be completely depleted within the next few decades due to its limited source and the high rate of mining. This potential for scarcity has only increased its appeal among collectors and jewelry enthusiasts.
Gemological Properties
Tanzanite is a relatively soft gemstone compared to diamonds or sapphires, but it is still durable enough for jewelry use when properly cared for. Its key gemological properties are as follows:
- Chemical Formula: Ca₂Al₃(SiO₄)(Si₂O₇)O(OH)
- Hardness (Mohs Scale): 6 to 7
- Refractive Index: 1.69 to 1.70
- Specific Gravity: 3.1 to 3.4
- Color: Deep blue to violet, with blue being the most valuable
- Crystal System: Monoclinic
- Luster: Vitreous (glassy)
- Cleavage: Perfect in one direction
- Transparency: Transparent to translucent
- Treatment: Heat-treated to enhance color
Tanzanite's color is one of its most distinguishing features. In its natural state, the stone tends to exhibit a reddish or brownish hue. However, when heated to temperatures between 500 and 600 degrees Celsius, the stone undergoes a transformation that reveals its deep blue and violet tones. This heat treatment is permanent and does not alter the gemstone's chemical composition.
The gemstone's monoclinic crystal structure gives it a unique optical property known as pleochroism, meaning that it can display different colors depending on the angle from which it is viewed. Tanzanite is trichroic, which means it can show three different colors: blue, violet, and brown. Skilled gem cutters take advantage of this property by orienting the stone to maximize the display of its most desirable colors.
Tanzanite is typically cut into faceted shapes such as emerald cuts, oval cuts, and princess cuts. These cuts help to enhance the gemstone's brilliance and color. Due to its moderate hardness and cleavage, tanzanite is best suited for jewelry that is worn on the body rather than for rings that are subject to frequent impact.
Symbolism and Metaphysical Beliefs
Tanzanite is not only valued for its beauty but also for its symbolic and metaphysical significance. In many cultures, the gemstone is associated with transformation, spiritual growth, and emotional healing. Its deep blue and violet hues are often linked to the night sky, representing depth, wisdom, and the mysteries of the universe.
One of the most popular beliefs surrounding tanzanite is its ability to facilitate communication and enhance psychic abilities. It is said to stimulate the throat, third-eye, and crown chakras, which are believed to be the centers of communication, intuition, and spiritual connection. As a result, tanzanite is often used in meditation and spiritual practices to help individuals tap into their higher consciousness and connect with the divine.
Tanzanite is also considered a stone of emotional healing. It is believed to help individuals release negative emotions, such as fear, anger, and sadness, and to promote a sense of calm and inner peace. This makes it a popular gemstone for those who are going through periods of change or personal transformation.
In some traditions, tanzanite is associated with the winter solstice, which marks the turning point of the year and the beginning of a new cycle. As December is the month of the winter solstice in the Northern Hemisphere, tanzanite is seen as a symbol of renewal and the light that follows darkness. This symbolism makes it a meaningful gift for those born in December or for those celebrating important milestones such as anniversaries or new beginnings.
Care and Cleaning
Due to its moderate hardness and cleavage, tanzanite requires careful handling and cleaning to maintain its beauty and integrity. Proper care is essential to prevent damage and ensure that the gemstone remains in excellent condition for years to come.
Cleaning: Tanzanite should be cleaned gently using a soft cloth or a mild soapy water solution. It is important to avoid using abrasive materials or harsh chemicals, as these can scratch or dull the surface of the stone. Ultrasonic and steam cleaners should also be avoided, as they can cause damage to the gemstone.
To clean tanzanite jewelry, follow these steps: 1. Mix a small amount of mild dish soap with lukewarm water. 2. Soak the jewelry in the solution for a few minutes. 3. Gently scrub the gemstone with a soft brush or cloth. 4. Rinse the jewelry thoroughly with clean water. 5. Pat dry with a soft, lint-free cloth.
Storage: Tanzanite should be stored separately from other gemstones to prevent scratching or chipping. A soft pouch or a lined jewelry box is ideal for storing tanzanite jewelry. Avoid exposing the gemstone to direct sunlight for extended periods, as this can cause fading or discoloration.
Wearing: Tanzanite is best suited for jewelry that is worn on the body, such as earrings, pendants, and bracelets. It is not recommended for rings that are worn on the fingers, as these are more likely to be subjected to impact and abrasion.
Repair and Re-Treatment: If tanzanite becomes damaged or loses its luster, it can often be re-polished by a professional jeweler. However, it is important to note that tanzanite is typically heat-treated to enhance its color, and this treatment is permanent. If the stone is exposed to high heat or harsh chemicals, it may lose its vibrant blue-violet hue.
Conclusion
Tanzanite is a gemstone of rare beauty, rich symbolism, and deep cultural significance. Discovered in 1967 in the Merelani Hills of Tanzania, this gemstone has captivated the world with its deep blue-violet hues and its unique geological origin. As the birthstone for December, tanzanite represents transformation, spiritual growth, and emotional healing, making it a meaningful and cherished gem for those born in this month.
Its geological properties, including its chemical composition, hardness, and pleochroism, make it a fascinating subject for gemologists and jewelry enthusiasts alike. While it requires careful handling and cleaning to preserve its beauty, tanzanite remains a popular choice for jewelry due to its elegance and exclusivity.
As one of the rarest gemstones on Earth, tanzanite serves as a reminder of the beauty and mystery that can be found in nature. Its limited supply and the possibility of its eventual depletion only add to its allure, making it a gemstone that will be treasured for generations to come.