Tanzanite is a relatively recent addition to the world of gemstones, yet it quickly gained prominence as a captivating December birthstone. Discovered in Tanzania in 1967, this blue-violet variety of the mineral zoisite owes much of its initial success to the marketing efforts of Tiffany & Co., who recognized its potential to rival the more established sapphire. This article will explore the history, geological origins, gemological properties, and significance of tanzanite, drawing exclusively from available sources.
History and Lore
Prior to 1967, tanzanite was unknown to the gemological world. The story of its discovery begins with the Maasai people of northern Tanzania, who noticed blue crystals while tending to their livestock in the Merelani Hills. These crystals were brought to the attention of a prospector named Manuel d’Souza, who initially believed them to be sapphire. He promptly registered four mining claims, setting in motion the gem’s journey to international recognition.
However, it was Tiffany & Co. who truly propelled tanzanite into the spotlight. Recognizing its unique color and potential, the company secured a distribution agreement and launched a major advertising campaign in 1968. Crucially, they decided the scientific name, “blue-violet zoisite,” lacked consumer appeal and instead christened the gem “tanzanite” in honor of its Tanzanian origin. This branding decision proved highly effective, and tanzanite quickly became a sensation. The gem was officially adopted as a December birthstone in 2002 by the American Gem Trade Association, marking the first change to their birthstone list since 1912. Today, it is also recognized as the gem for the 24th wedding anniversary.
Geological Formation and Sources
Tanzanite is exceptionally rare, found commercially only in a small area – the Merelani Hills of northern Tanzania. This limited geographical source contributes significantly to its value and desirability. The gem forms within metamorphic rocks, a result of intense heat and pressure. The mining operations in the Merelani Hills range from small-scale artisanal digging to larger, mechanized operations extending over 100 meters deep into the earth. The landscape surrounding the mines is characterized by grass-covered hillsides, scrub brush, and rocky soil, overlooked by the snow-covered slopes of Mount Kilimanjaro.
The concentration of tanzanite within this small area is geologically unique, leading some to speculate about its long-term availability. Sources indicate that the mining area spans only a few square miles, further emphasizing the gem’s rarity.
Gemological Properties
Tanzanite is a blue to violet variety of the mineral zoisite, a calcium aluminum silicate. Its color ranges from a pure, rich blue to violet, with the blue shades generally considered the most valuable. The gem is often described as “velvety” due to its deep and saturated color. A key characteristic of tanzanite is its pleochroism, meaning it can display different colors when viewed from different angles. This phenomenon is a result of its crystal structure and contributes to its visual appeal.
Most tanzanite found in the market undergoes heat treatment to enhance its blue hues and minimize brown tones. This treatment is a standard practice and is widely accepted within the gem trade. However, sources do not provide specific details regarding the heat treatment process.
While visually striking, tanzanite is not as hard as some other popular gemstones. This relative softness requires careful handling and consideration when designing jewelry. Designers often employ protective settings, such as invisible bezel prongs, to safeguard the stone from damage. Specific gemological data, such as refractive index or chemical formula, are not provided within the available sources.
Symbolism and Metaphysical Beliefs
While the sources primarily focus on the gem’s history and geological properties, some cultural beliefs surrounding tanzanite are mentioned. In Tibetan tradition, turquoise – one of the other December birthstones – is considered a national treasure believed to grant health, good fortune, and protection from evil. While no specific metaphysical properties are directly attributed to tanzanite within the provided sources, the association with the color blue often carries connotations of peace, tranquility, and wisdom.
Historically, turquoise held significant meaning for various cultures. The Apache believed turquoise could be found by following a rainbow to its end and that attaching it to weaponry improved accuracy. The Pueblo people associated its color with the sky, while the Hopi believed it was created by lizards scurrying across the earth. In European tradition, a turquoise ring symbolized “forget me not.”
Care and Cleaning
Due to its relatively lower ranking on the Mohs hardness scale compared to diamonds or rubies, tanzanite requires careful handling. The sources suggest that jewelry designers utilize protective settings to minimize the risk of damage. Specific cleaning instructions are not provided, but general guidelines for gemstones of similar hardness would apply: avoid harsh chemicals, ultrasonic cleaners, and abrasive materials. Gentle cleaning with warm, soapy water and a soft cloth is recommended.
Conclusion
Tanzanite stands as a remarkable example of a 20th-century gemstone discovery. From its humble beginnings in the Merelani Hills of Tanzania to its elevation as a coveted December birthstone, its story is one of geological rarity, astute marketing, and enduring beauty. The gem’s unique color, pleochroism, and limited source contribute to its appeal, while its relative softness necessitates careful handling. Though a newcomer to the world of colored stones, tanzanite has firmly established itself as a significant and cherished gemstone.