For individuals born in December, the choice of a birthstone is not limited to a single gem but is enriched by a vibrant trio: tanzanite, turquoise, and zircon. Each of these stones offers a distinct expression of the month's cool, wintry palette, ranging from the deep violet-blue of tanzanite to the serene sky blue of turquoise and the brilliant, multi-faceted fire of zircon. This unique collection provides a spectrum of options, allowing for personal preference in both color and character. The significance of these gems extends beyond mere aesthetics, encompassing deep historical roots, rare geological origins, and a wealth of cultural symbolism that has captivated humanity for centuries.
This comprehensive guide will explore the individual journeys of tanzanite, turquoise, and zircon. We will delve into their rich histories and lore, examining how each stone has been revered across different eras and cultures. Furthermore, we will investigate the geological processes that give rise to these remarkable minerals and identify the specific regions of the world where they are sourced. A detailed analysis of their gemological properties, including hardness, chemical composition, and unique optical characteristics, will provide a scientific foundation for understanding their value and appeal. Finally, the article will touch upon the metaphysical beliefs associated with each gem and offer practical advice on their care and maintenance, ensuring these precious stones can be cherished for generations.
History and Lore
The tradition of birthstones is deeply rooted in history, with its origins tracing back to ancient beliefs and the breastplate of Aaron described in the Bible. Over time, these traditions have evolved, and for December, the list has expanded to include tanzanite, turquoise, and zircon, each carrying its own unique narrative.
Tanzanite: A Modern Marvel
Tanzanite stands out as one of the most recent additions to the world of colored gemstones and, consequently, to the list of birthstones. Its story began in 1967, when a Maasai tribesman in the Merelani Hills of Tanzania discovered unusual blue-violet crystals exposed on the ground. This serendipitous find marked the beginning of a new chapter in gemology. The gemstone was initially marketed under the name "zandrite," but this was soon changed to "tanzanite" in honor of its exclusive country of origin. The rarity of tanzanite cannot be overstated; it is found in only one location on the entire planet—near the majestic Mount Kilimanjaro in Tanzania. This geographical exclusivity contributes significantly to its allure and value.
Turquoise: The Ancient Talisman
In stark contrast to tanzanite's modern history, turquoise is the oldest and most traditional of the December birthstones, with a legacy spanning thousands of years. Its use and reverence can be traced back to ancient civilizations across the globe. Historical accounts note that turquoise has been cherished by royalty, such as the famed Egyptian Pharaoh King Tutankhamun, who was buried with treasures adorned with this vibrant stone. For millennia, turquoise was believed to be a protective talisman, capable of safeguarding its wearer from harm, including falls and negative energy. Its enduring popularity is a testament to its timeless appeal and deep-seated cultural significance.
Zircon: The Old Mineral with Dazzling Fire
Zircon is an old mineral that has captivated gem enthusiasts for centuries with its exceptional brilliance and fire. While its history is long, its identity is sometimes confused due to its similarity in name to the man-made cubic zirconia. However, natural zircon is one of the oldest minerals on Earth, and its dazzling sparkle has been admired since antiquity. Historically, zircon was associated with wisdom, a sense of balance, and mental clarity. Its ability to display fiery flashes of light has made it a popular choice for jewelry throughout the ages, solidifying its place as a cherished December gem.
The journey of these three stones to becoming recognized December birthstones reflects an evolution in tradition. While turquoise has long held the position, the inclusion of zircon and later tanzanite provided a wider array of colors and styles, catering to modern tastes while honoring the rich history of each gem.
Geological Formation and Sources
Understanding the geological origins of tanzanite, turquoise, and zircon reveals the unique conditions required to create these gems and highlights the specific regions of the world that yield them.
Tanzanite: A Singular Geological Anomaly
Tanzanite's formation is as unique as its single source location. It is a variety of the mineral zoisite and owes its captivating blue-to-violet color to the presence of vanadium within its crystal structure. The geological conditions that created tanzanite were highly specific and, to date, have only been found in the Merelani Hills of Tanzania. This area near Mount Kilimanjaro experienced a unique set of geological events that allowed for the formation of these particular zoisite crystals. The rarity of these conditions is the primary reason why tanzanite is considered one of the rarest gems in the world, with experts estimating its supply may be finite.
Turquoise: A Product of Arid Lands
Turquoise is not formed from a single mineral but is a hydrous phosphate of copper and aluminum. Its formation occurs in arid regions where acidic, copper-rich groundwater seeps through pre-existing rocks containing aluminum and phosphorus. Over millions of years, this process precipitates turquoise in veins and nodules. The most significant sources for turquoise are found in such environments, particularly in the southwestern United States (Arizona, New Mexico, Nevada), Iran, Egypt, China, Mexico, and parts of Central Asia and Africa. The presence of a "matrix"—a web-like pattern of host rock within the turquoise—often indicates its origin and can add to its unique character. The most prized varieties, such as Persian turquoise and Sleeping Beauty Turquoise from Arizona, are celebrated for their vivid, even color and minimal to absent matrix.
Zircon: A Mineral Found Worldwide
Unlike the geographically exclusive tanzanite, zircon is a common mineral found in many parts of the world. It is a zirconium silicate (ZrSiO₄) and is found in igneous, metamorphic, and sedimentary rocks. Significant commercial sources for gem-quality zircon include Cambodia, Sri Lanka, Thailand, Australia, and parts of Africa. The formation of zircon crystals occurs in a variety of geological settings, allowing for a more widespread distribution. However, the specific conditions required to produce the vibrant colors and high clarity desired for gemstones are less common, making fine zircon a treasured find.
Gemological Properties
The value, durability, and appearance of a gemstone are defined by its gemological properties. Each of the December birthstones possesses a distinct set of characteristics that discerning buyers and jewelers must consider.
Tanzanite
Tanzanite is a member of the zoisite species. Its most defining feature is its strong trichroism, meaning it can display three different colors when viewed from three different crystallographic directions: blue, violet, and a reddish hue. Gem cutters must orient the rough stone carefully to showcase the desired blue-violet color in the finished gem. On the Mohs scale of hardness, tanzanite registers between 6 and 7, making it moderately durable but susceptible to scratching and chipping if not handled with care. It is typically heat-treated to enhance its blue color, a standard and stable practice in the industry. Its specific gravity ranges from 3.28 to 3.35, and it has a refractive index of 1.690 to 1.700.
Turquoise
Turquoise is an opaque gemstone, valued for its distinctive color rather than its brilliance. Its chemical composition is a hydrated phosphate of copper and aluminum, which is responsible for its characteristic blue and green hues. The presence of copper results in a blue color, while iron imparts a greenish tint. Turquoise ranks between 5 and 6 on the Mohs scale, making it relatively soft and porous. This porosity means it can be susceptible to damage from chemicals, cosmetics, and even the natural oils of the skin, which can cause discoloration over time. Its specific gravity is typically between 2.6 and 2.9. The presence of the matrix—the host rock included in the gem—affects its appearance and is a key factor in identifying its origin and value.
Zircon
Zircon is renowned for its exceptional brilliance and fire, which can rival that of diamond. It has a high refractive index of 1.92 to 1.98 and strong dispersion (0.039), which is responsible for its dazzling play of light. Zircon is also pleochroic, meaning it can show different colors when viewed from different directions. While it is available in a range of colors, the bright blue variety is most associated with December. Zircon is relatively hard, registering a 6.5 to 7.5 on the Mohs scale, making it more durable than tanzanite and turquoise. However, it can be brittle due to its crystal structure. Its specific gravity ranges from 4.6 to 4.7.
| Gemstone | Chemical Composition | Mohs Hardness | Refractive Index | Key Characteristic |
|---|---|---|---|---|
| Tanzanite | Ca₂Al₃(SiO₄)₃(OH) (Zoisite variety) | 6 - 7 | 1.690 - 1.700 | Strong Trichroism (blue, violet, red) |
| Turquoise | Hydrated Copper Aluminum Phosphate | 5 - 6 | 1.610 - 1.650 (approx.) | Opaque, Porous, Matrix patterns |
| Zircon | ZrSiO₄ | 6.5 - 7.5 | 1.92 - 1.98 | High Brilliance and Fire (Dispersion) |
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, tanzanite, turquoise, and zircon are steeped in symbolism and are believed by many to possess metaphysical properties that can influence the wearer's life and well-being.
Turquoise: The Stone of Protection and Wisdom
As one of the oldest gemstones in human history, turquoise carries a heavy weight of symbolism. It is widely regarded as a stone of protection, good fortune, and tranquility. Across many cultures, it was believed to ward off evil spirits and protect the wearer from physical harm, such as falls or accidents. Today, turquoise is often associated with wisdom, tranquility, and friendship. Many people turn to this stone for its perceived grounding energy, which helps to bring a sense of calm and stability when life feels chaotic. Its steady, calming presence is a source of comfort for those who wear it.
Tanzanite: The Gem of Transformation and New Beginnings
Reflecting its recent discovery and unique violet-blue color, tanzanite is strongly linked to transformation, growth, and new chapters in life. Its energy is said to facilitate shifts in consciousness, encouraging the wearer to embrace change with clarity and curiosity. The stone is believed to enhance intuition and spiritual perception, making it a powerful tool for those on a journey of personal development. Its symbolism is particularly resonant for individuals undergoing significant life transitions, as it represents the anticipation of new beginnings, much like the end of the year that December represents.
Zircon: The Stone of Clarity and Balance
Zircon is traditionally associated with sharpening focus and boosting mental clarity. It is believed to help its wearer see things with a clearer perspective, aiding in decision-making and problem-solving. In addition to mental clarity, zircon is also linked to a sense of balance and honor. Its brilliant sparkle is thought to represent an inner light that guides one toward wisdom and truth. For centuries, it has been used as a talisman for travelers and a stone to promote honor and purity of spirit.
Care and Cleaning
Proper care is essential to maintain the beauty and integrity of any gemstone. Due to their differing physical properties, each of the December birthstones requires a specific approach to cleaning and handling.
Caring for Tanzanite
With a Mohs hardness of 6 to 7, tanzanite is moderately durable but can be damaged by sharp blows. It is also pleochroic, and its color can be altered by high heat, so it should not be exposed to extreme temperatures. To clean tanzanite jewelry, use warm water, a mild soap, and a soft brush. Ultrasonic and steam cleaners are generally not recommended, as the vibrations and heat can cause damage. It is best to store tanzanite pieces separately to prevent them from being scratched by harder gems.
Caring for Turquoise
Turquoise is the most delicate of the three December stones. Its porosity and relative softness (5-6 on the Mohs scale) make it vulnerable to chemicals, heat, and physical impact. Substances like perfume, hairspray, makeup, and even lotions can cause turquoise to become discolored or its surface to become dull over time. It should be wiped with a soft, dry cloth after each wear. For a more thorough cleaning, use a soft brush with lukewarm water and a small amount of mild soap, then rinse and dry completely immediately. Avoid ultrasonic cleaners, steam cleaners, and harsh chemicals entirely. Store turquoise away from other jewelry to prevent scratches.
Caring for Zircon
Zircon is relatively hard (6.5 to 7.5) but can be brittle. It is important to avoid sharp impacts that could cause the gem to chip or crack. Zircon can also be sensitive to heat, so it is wise to avoid exposing it to sudden temperature changes. Standard cleaning methods are generally safe: warm water, mild detergent, and a soft brush. Ultrasonic cleaners are usually safe for zircon, but it is always best to confirm with a professional jeweler, especially if the stone has been treated or has inclusions. As with other gems, store zircon pieces separately to protect them from being scratched by harder materials.
Conclusion
The birthstones of December—tanzanite, turquoise, and zircon—offer a remarkable trio that combines ancient history with modern discovery, geological rarity with widespread beauty, and profound symbolism with tangible physical properties. From the protective, ancient talisman of turquoise to the transformative, singularly sourced tanzanite and the clarifying, brilliant fire of zircon, each gem provides a unique narrative and aesthetic. Together, they form a collection that perfectly captures the essence of December: a time of transition, reflection, and anticipation for the new beginnings to come. Their diverse colors, histories, and characteristics ensure that anyone born in this month can find a gemstone that not only adorns them with beauty but also resonates with their personal style and spiritual inclinations.