In the final month of the year, as the Northern Hemisphere settles into winter and the Southern Hemisphere embraces summer, a unique celestial alignment occurs. The Geminid meteor shower, one of the year's most spectacular displays, streaks across the December night sky. This month, marked by holidays of light and reflection, is traditionally associated with not one, but three distinct birthstones: turquoise, zircon, and tanzanite. Each of these gems carries a rich tapestry of history, geological origin, and cultural symbolism, offering a diverse palette of color and meaning for those born under the Sagittarius and Capricorn signs. This article delves into the properties, origins, and lore of these three December birthstones, exploring why they have been chosen to represent this pivotal month of the year.
The Traditional Gem: Turquoise
Turquoise is the most ancient and traditionally recognized birthstone for December. Its name, derived from the French pierre turquoise meaning "Turkish stone," reflects its historical trade routes from Persia to Europe. For millennia, this opaque, sky-blue to greenish-blue mineral has been a symbol of protection, good fortune, and success, as noted in historical and cultural accounts.
Geological Formation and Sources
Turquoise is a hydrous phosphate of copper and aluminum, formed in arid regions where acidic, copper-rich groundwater interacts with rocks containing aluminum and phosphorus. This process occurs over millions of years, creating veins and nodules within host rocks. While the exact geological formation process is not detailed in the provided materials, the sources confirm that turquoise has been mined for thousands of years. Historically, the most prized turquoise came from Persia (modern-day Iran), known for its intense, robin's-egg blue color. Other notable sources include the Southwestern United States, Egypt, and China. The provided materials do not specify current mining locations, but its historical significance is well-established.
Gemological Properties
Turquoise is characterized by its distinctive color, which can range from sky blue to greenish blue, often with a matrix of darker veining from the host rock. It has a hardness of 5 to 6 on the Mohs scale, making it relatively soft and susceptible to scratching. This porosity also means it can be prone to discoloration from chemicals, oils, and prolonged exposure to sunlight. The provided materials do not specify its refractive index or specific gravity, but its key property is its opacity and unique color, which is primarily due to the presence of copper. It is often treated or stabilized to enhance its durability and color, a common practice in the gem trade.
History and Lore
Turquoise's history is as deep as its color. Ancient Egyptians adorned themselves with turquoise jewelry, believing it offered protection in the afterlife. Persian warriors fitted their bows and daggers with turquoise, considering it a protective talisman. In Native American cultures of the American Southwest, turquoise is a sacred stone, deeply connected to the earth and sky. The provided sources emphasize its role as a "symbol of good fortune and success," a belief that has persisted across numerous cultures and eras. Its association with December likely stems from its vibrant, icy blue hue, reminiscent of winter skies and clear, cold days.
The Diverse Zircon
Often overshadowed by its synthetic counterpart, cubic zirconia, natural zircon is a historically significant and beautiful gemstone in its own right. It is one of the three modern birthstones for December, valued for its brilliance and range of colors.
Geological Formation and Sources
Zircon is a zirconium silicate mineral that forms as crystals within igneous and metamorphic rocks. It is one of the oldest minerals on Earth, with some crystals dating back billions of years. The provided sources mention that zircon "comes in a variety of colors but is most popular in its blue form." While the sources do not specify particular mining locations for December's zircon, it is found in many locations worldwide, including Australia, Cambodia, and Sri Lanka. The blue variety, which is most associated with December, is often heat-treated to achieve its vivid color, as natural blue zircon is relatively rare.
Gemological Properties
Zircon is renowned for its exceptional brilliance and fire, which can rival that of diamond. It has a high refractive index (approximately 1.92-2.01) and strong dispersion, which gives it its dazzling sparkle. On the Mohs scale, zircon has a hardness of 6.5 to 7.5, making it durable enough for jewelry, though it can be brittle due to its tetragonal crystal structure. The provided materials do not detail its chemical composition, but it is known to be zirconium silicate (ZrSiO₄). The most valued blue zircon exhibits a bright, vivid blue color, often compared to the sky on a clear day.
History and Lore
Zircon's history is ancient; it has been used in decorative objects and jewelry for centuries. In the Middle Ages, it was believed to promote sleep, bring prosperity, and ward off evil spirits. The blue variety, in particular, has been associated with wisdom and honor. While the provided sources do not delve deeply into its metaphysical beliefs, they acknowledge its status as a December birthstone, popular in its blue form. Its inclusion alongside turquoise and tanzanite offers a spectrum of blue hues, from the soft, opaque sky of turquoise to the brilliant, transparent blue of zircon.
The Modern Marvel: Tanzanite
The youngest of the three December birthstones, tanzanite was discovered in the 20th century and quickly captivated the gem world with its unique color and rarity.
Geological Formation and Sources
Tanzanite's formation is as unique as its color. It is a variety of the mineral zoisite, colored by trace amounts of vanadium. The provided sources state that tanzanite "was discovered in Tanzania in 1967 and is rarer than diamonds." Its formation is linked to a specific geological event—the metamorphism of rocks under unique conditions in the Merelani Hills of Tanzania. This single-source origin, confined to a small area in the foothills of Mount Kilimanjaro, is what makes tanzanite exceptionally rare. The sources confirm its discovery date and location, highlighting its modern provenance.
Gemological Properties
Tanzanite is prized for its dramatic, saturated color, which ranges from a pure, ultramarine blue to a vibrant violet-blue. It exhibits strong trichroism, meaning it can show three different colors—blue, violet, and burgundy—depending on the crystal orientation. With a hardness of 6 to 7 on the Mohs scale, it is suitable for jewelry but requires careful handling. The provided materials note its rarity, stating it is "rarer than diamonds," a claim based on its extremely limited geographical occurrence. Its chemical composition is calcium aluminum silicate hydroxide (Ca₂Al₃(SiO₄)₃(OH)), with vanadium as the coloring agent.
History and Lore
Tanzanite's history is remarkably brief. Before its discovery in 1967, it was unknown to the gemological world. Its sudden appearance on the market, with its stunning color and compelling story of single-source origin, led to its rapid rise in popularity. While the provided sources do not detail ancient lore, its modern symbolism is tied to its unique journey from the earth to the jewelry box. It is often associated with transformation and new beginnings, fitting for a gem discovered in the modern era. Its inclusion as a December birthstone in 2002 by the American Gem Trade Association (AGTA) reflects its acceptance as a significant and valuable gem.
Symbolism and Cultural Significance of December's Gems
The selection of turquoise, zircon, and tanzanite as December's birthstones is not arbitrary. Each gem reflects different aspects of the month and the winter season.
Turquoise, with its sky-blue color, symbolizes the clear, cold winter skies and is a talisman of protection and good fortune—a fitting wish for the year's end and a new beginning. Its historical use as a protective stone across cultures from Persia to the American Southwest underscores its universal appeal.
Zircon, with its brilliant sparkle and range of colors, represents the festive lights of December's holidays. The blue variety, in particular, mirrors the deep, clear winter nights and the brilliance of stars. Its historical associations with wisdom and prosperity align with the reflective nature of the year's end.
Tanzanite, the modern gem, represents the unique and the rare. Its discovery in 1967 adds a contemporary narrative to the ancient traditions of birthstones. Its vibrant, dual-tone color (blue and violet) captures the complexity of the winter season—a time of both stillness and vibrant celebration.
Together, these three stones offer a diverse yet cohesive palette for December. They provide options for different tastes and styles, from the classic, opaque charm of turquoise to the fiery brilliance of zircon and the modern, saturated color of tanzanite.
Care and Cleaning
The physical properties of these gems dictate how they should be cared for. Understanding their hardness and stability is crucial for maintaining their beauty.
- Turquoise (Hardness: 5-6): As a relatively soft and porous stone, turquoise requires gentle care. It should be cleaned with a soft, dry cloth. Avoid ultrasonic cleaners, steam cleaners, and harsh chemicals, as these can damage the stone and any stabilizing treatments. Store it separately to prevent scratching.
- Zircon (Hardness: 6.5-7.5): Zircon is more durable than turquoise but can be brittle. It is safe to clean with warm, soapy water and a soft brush. Avoid sudden temperature changes, which can cause fractures. Its brilliance can be maintained with regular, gentle cleaning.
- Tanzanite (Hardness: 6-7): Tanzanite is moderately hard but has perfect cleavage in one direction, making it susceptible to breaking if struck with force. Clean it with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and extreme temperature changes. Due to its cleavage, it should be stored carefully, preferably in a soft pouch.
Conclusion
The month of December is uniquely represented by a trio of gemstones, each with its own distinct character and story. Turquoise, the ancient talisman of protection and good fortune, offers timeless, sky-blue elegance. Zircon, the brilliant and historically significant gem, provides dazzling sparkle and a spectrum of colors, with blue being the most sought-after for this month. Tanzanite, the modern marvel from Tanzania, captivates with its rare, vivid violet-blue hue and a history spanning only decades. Together, they embody the spirit of December—a month of reflection, celebration, and the promise of a new year. For those born in this final month, these stones offer a connection to deep history, geological wonder, and cultural symbolism, making them far more than mere decoration; they are personal talismans of identity and meaning.