Tanzanite is a captivating gemstone, recognized as a December birthstone, distinguished by its striking pleochroism and relatively recent discovery in the 20th century. This article will delve into the history, geological origins, gemological properties, and cultural significance of this vibrant blue-violet gem, drawing exclusively from available sources.
History and Lore
While the tradition of birthstones dates back centuries, with roots in ancient Poland around the 17th century and a formalized list published in the United States in 1912, tanzanite is a comparatively modern addition to the birthstone canon. The story of tanzanite began in 1962 when blue stones emerging from Tanzania were identified as the mineral zoisite. However, the primary source of this December birthstone wasn’t located until 1967 in the Merelani Hills. It was subsequently named tanzanite in honor of its country of origin.
The gem’s initial introduction to the market was largely driven by Tiffany & Co., who recognized its potential for international appeal. In 1968, Tiffany launched a significant advertising campaign to promote tanzanite, highlighting its vivid colors, high clarity, and potential for large cut stones. This campaign quickly propelled tanzanite to prominence, establishing it not only as a December birthstone but also as the gem commemorating the 24th wedding anniversary.
Geological Formation and Sources
Tanzanite’s geological uniqueness is underscored by the fact that the Merelani Hills of northern Tanzania is the only place on Earth where it is commercially mined. The mining operations, both mechanized and small-scale, extend over 100 meters (more than 300 feet) into the earth. The landscape surrounding the mines is characterized by grass-covered hillsides, scrub brush, and rocky soil, with the snow-covered slopes of Mount Kilimanjaro looming in the distance. The formation of tanzanite itself is a complex geological process, tied to the unique metamorphic conditions found in this specific region of Tanzania.
Gemological Properties
Tanzanite is described as “velvety” due to its deep and saturated color, which ranges from a pure rich blue to violet. The blue variety is considered the most valuable. The gem is renowned for its trichroism, meaning it can display three different colors depending on the viewing angle. This characteristic contributes to its captivating appearance and the skill required to cut it in a way that maximizes its brilliance and color. While specific details like refractive index and chemical formula are not provided in the available sources, the sources do highlight its clarity and potential for large cut stones as key attributes.
Symbolism and Metaphysical Beliefs
The provided sources do not detail extensive metaphysical beliefs associated with tanzanite. However, the sources do mention that garnets, another December birthstone, were believed to have protective properties and were popular amongst warriors and royalty, associated with vitality and light. Lapis lazuli, also a traditional December birthstone, has long been associated with wisdom and royalty, considered a stone of truth and enlightenment. Turquoise, another December birthstone, is believed to instill a sense of inner calm and foster creativity. While these associations apply to other December birthstones, no specific symbolism is directly attributed to tanzanite within the provided materials.
Care and Cleaning
Specific care instructions for tanzanite are not detailed in the provided sources. However, information regarding moonstone, a gem with similar hardness, offers some guidance. Moonstone, with a Mohs hardness of 6–6.5, should not be cleaned with ultrasonic or steam cleaners due to its poor toughness and susceptibility to cracking when exposed to high heat. The recommended cleaning method is warm, soapy water with a soft brush. This suggests a similar gentle approach would be prudent for tanzanite, given its potential for sensitivity.
Comparison to Other Birthstones
The provided sources offer a comparative context by detailing other birthstones. Garnet, a January birthstone, exists in several varieties, including the classic red rhodolite and the rarer demantoid and tsavorite. Moonstone, a June birthstone, is known for its adularescence, a shimmering effect. Pearls, also a June birthstone, have historically symbolized purity and innocence. Lapis lazuli, a traditional December birthstone, is a composite rock composed of lazurite, calcite, and pyrite, exhibiting a deep blue hue. Turquoise, another December birthstone, displays captivating blue-green hues and has been revered for centuries across various cultures. These comparisons highlight the diverse range of gemstones associated with different months and their unique characteristics.
Historical Context of Birthstones
The concept of birthstones has a long and evolving history. While the traditional list of birthstones is believed to have originated in Poland around the 17th century, the modern list commonly used today was published in the United States in 1912 by the National Jewelers Association. This list has been updated several times, resulting in some months having multiple gemstone options. This evolution reflects changing cultural preferences and the discovery of new gemstones. The historical context underscores the dynamic nature of birthstone traditions and the ongoing influence of gemological discoveries.
Turquoise: A December Alternative
The sources also detail the historical significance of turquoise as a December birthstone. Turquoise has been used since at least 3000 BCE in ancient Egypt, associated with protection and good fortune. In Persia (modern-day Iran), it was believed to protect against unnatural activities and enhance spiritual significance. Among Native American cultures, particularly the Navajo, Zuni, and Pueblo peoples, turquoise is considered a sacred stone embodying the spirit of the sky and water, often incorporated into intricate silver jewelry.
Lapis Lazuli: A Traditional December Stone
Lapis lazuli, another traditional December birthstone, is a composite rock comprised of lazurite, calcite, and pyrite, resulting in a deep blue color with white streaks and golden sparkle. It has a Mohs hardness of 5 to 6, making it suitable for various jewelry applications. Historically, lapis lazuli was associated with wisdom and royalty, believed to enhance intellectual abilities and stimulate a quest for knowledge. It was also used for enhancing mental and physical well-being and given as gifts for engagements, weddings, and anniversaries.
Pearls: A June Gem with Rich History
The sources also provide information on pearls, a June birthstone, historically associated with purity, humility, and innocence. Pearls were traditionally given as wedding gifts and believed to bestow long life and prosperity. The La Peregrina, a 50.56-carat pearl discovered in the 1500s, is a famous example of a natural pearl, once owned by European royalty and later gifted to Elizabeth Taylor. Pearls are found in warm waters and are often cultivated on pearl farms located in remote and scenic locations.
Conclusion
Tanzanite, a relatively recent addition to the world of gemstones, has quickly established itself as a highly sought-after December birthstone. Its unique trichroism, vibrant color, and limited source contribute to its allure. While its historical lore is still developing compared to more ancient gems like turquoise and lapis lazuli, tanzanite’s captivating beauty and the story of its discovery continue to fascinate gemstone enthusiasts and jewelry lovers alike. The gem’s association with Tiffany & Co. and its rise to prominence in the late 20th century demonstrate the power of marketing and the enduring appeal of rare and beautiful gemstones.