The world of gemstones is rich with history, lore, and scientific fascination. Among the most captivating are the birthstones, each associated with a particular month and imbued with unique significance. For those born in December, a selection of beautiful blue gemstones offers a choice, with tanzanite being a relatively recent addition to this esteemed group. This article will explore the history, geological origins, gemological properties, and cultural significance of tanzanite, alongside its place within the broader context of December birthstones.
The tradition of associating gemstones with specific months dates back to antiquity, with roots in the biblical breastplate of Aaron, adorned with twelve stones representing the tribes of Israel. Over time, this practice evolved, with different cultures and eras assigning various gems to each month, often based on color. The standardization of birthstones began in 1912 with the American Gem Society, and the list has been modified several times since, most recently with the addition of tanzanite in 2002. This addition reflects both the growing popularity of the gem and a desire to offer a wider range of choices for those seeking a meaningful birthstone.
A Recent Addition to a Timeless Tradition
The concept of birthstones has a long and fascinating history, originating in ancient times with the belief that gemstones possessed healing powers and influenced fate. The association of twelve stones with the months of the year began to solidify in the 18th century, evolving from earlier connections to zodiac signs. The official standardization of birthstones in the United States occurred in 1912, but the list wasn’t static. In 1952, alexandrite, citrine, tourmaline, and zircon were added, and in 2002, tanzanite joined the ranks of December birthstones, alongside blue topaz, blue zircon, and turquoise. This demonstrates the ongoing evolution of the birthstone tradition, adapting to new discoveries and preferences.
The Discovery and Origins of Tanzanite
Tanzanite is a relatively recent discovery in the world of gemstones. It was first found in the Merelani Hills of northern Tanzania in 1967, near the base of Mount Kilimanjaro. The discovery is attributed to a Maasai tribesman, Manuel d’Souza, who stumbled upon the vibrant blue crystals. Initially, the gem was misidentified as sapphire due to its striking color. However, subsequent gemological analysis revealed it to be a unique variety of the mineral zoisite.
The gem was quickly recognized for its exceptional pleochroism – the ability to display different colors when viewed from different angles. This characteristic, combined with its intense blue-violet hue, captivated the attention of the gem world. Tiffany & Co. played a pivotal role in popularizing tanzanite, naming it after its country of origin and launching a successful marketing campaign.
Tanzanite is found in a very small mining area – approximately eight square kilometers – making it exceptionally rare. This limited geographical source contributes to its value and desirability. The gem is formed within metamorphic rocks, created by intense heat and pressure.
Gemological Characteristics
Tanzanite is a calcium aluminum silicate mineral with a chemical formula of Ca2Al3(SiO4)3(OH). It belongs to the zoisite family, which also includes thulite and emerald. Its hardness on the Mohs scale is 6.5 to 7, making it relatively durable but susceptible to scratching. It exhibits a vitreous luster and possesses a perfect cleavage, meaning it can split along specific planes.
The color of tanzanite is its most defining characteristic. It typically ranges from deep blue to violet-blue, with some stones exhibiting a reddish-purple hue. The color is influenced by trace amounts of vanadium within the crystal structure. Most tanzanite is heat-treated to enhance its blue color, a process that is widely accepted and stable.
Here's a summary of key gemological properties:
| Property | Value |
|---|---|
| Chemical Formula | Ca2Al3(SiO4)3(OH) |
| Hardness (Mohs) | 6.5 - 7 |
| Luster | Vitreous |
| Cleavage | Perfect |
| Pleochroism | Present |
| Crystal System | Triclinic |
Symbolism and Cultural Significance
While tanzanite’s history is relatively short compared to many other birthstones, it has quickly acquired symbolic meaning. It is often associated with transformation, intuition, and spiritual awareness. Some believe it promotes communication and helps to connect with one’s higher self. Its vibrant blue color is often linked to tranquility, wisdom, and serenity.
As a December birthstone, tanzanite offers an alternative to the more traditional blue topaz, blue zircon, and turquoise. It is a popular choice for those seeking a unique and modern gemstone with a captivating story. The gem is also frequently given as a gift to commemorate significant milestones, such as anniversaries.
Care and Cleaning
Due to its hardness and perfect cleavage, tanzanite requires careful handling and cleaning. It is susceptible to scratching from harder materials, so it should be stored separately from diamonds and other abrasive gemstones. Cleaning can be done with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and harsh chemicals, as these can damage the stone. It is also advisable to have tanzanite jewelry professionally inspected and cleaned periodically to ensure its longevity.
Tanzanite in the December Birthstone Landscape
December boasts a rich selection of birthstones, each with its own unique appeal. Blue topaz, known for its affordability and vibrant blue hues, is a popular choice. Blue zircon, with its high refractive index and brilliance, offers a sparkling alternative. Turquoise, a longstanding symbol of protection and good fortune, provides a touch of Southwestern charm. Tanzanite, with its captivating pleochroism and relatively recent discovery, adds a modern and sophisticated option to the December birthstone collection. The addition of tanzanite in 2002 broadened the choices available to those born in December, allowing individuals to select a gemstone that resonates with their personal style and preferences.
Conclusion
Tanzanite is a remarkable gemstone with a captivating history, unique gemological properties, and growing cultural significance. Its discovery in Tanzania in 1967 and subsequent popularization by Tiffany & Co. have established it as a highly sought-after gem. As a December birthstone, it offers a vibrant and modern alternative to traditional choices, symbolizing transformation, intuition, and spiritual awareness. Its limited source and exceptional beauty ensure that tanzanite will continue to be treasured by gem enthusiasts and jewelry lovers for generations to come.