The month of December is uniquely graced by a trio of birthstones, each offering a distinct palette of cool blues and greens that mirror the winter sky and icy landscapes. Turquoise, Tanzanite, and Zircon are the official gemstones for those born in this final month of the year, associated with the zodiac signs of Sagittarius (November 22 – December 21) and Capricorn (December 22 – January 19). These gems are not merely decorative; they are steeped in millennia of history, geological wonder, and cultural symbolism. From the ancient protective amulets of Persia to the modern discovery of a singularly brilliant blue-violet stone, the December birthstones represent a fascinating convergence of tradition, science, and personal meaning. This article delves into the rich tapestry of these three gems, exploring their historical lore, geological origins, gemological properties, and the symbolic attributes that make them cherished by collectors and wearers alike.
History and Lore: A Journey Through Time
The historical significance of the December birthstones spans continents and epochs, with each gem carrying its own narrative of human fascination.
Turquoise: The Stone of the Sky Turquoise is arguably the oldest birthstone in the December collection, with a documented history stretching back over 3,000 years. Its name derives from the French phrase pierre turquoise, meaning "stone of Turkey." This nomenclature arose because the gem was brought to Europe from Turkish bazaars, though its primary sources were in Persia and along the Sinai Peninsula, transported through gem markets in Constantinople (modern-day Istanbul). From its earliest days, turquoise was a favored material for amulets due to its relative softness, which made it easy to carve and inscribe. It was believed to possess protective powers against danger and was expected to bring good fortune. In ancient Persia, it was prized by lovers and married couples as a gemstone that safeguarded relationships and preserved friendship when given as a gift. A common belief held that turquoise could warn its wearer of approaching illness or danger by becoming pale. This lore extended across cultures; Tibetans considered it a birthstone of fortune, health, and success, and it was often used as a currency. Ancient Incas and Mayas offered turquoise to their gods, while Native Americans of the Southwest associated it with youth and strength. Its sacred status in many cultures is a testament to its enduring appeal.
Zircon: The Fiery Sparkle of Antiquity Zircon, particularly the blue variety, has a long history of use in jewelry, appearing prominently in antique Victorian pieces often set in gold to highlight its fiery sparkle. While specific ancient lore for blue zircon is less detailed in the provided sources compared to turquoise, its inclusion in historical jewelry underscores its value as a gemstone of enduring beauty. The traditional status of zircon as a December birthstone connects it to a lineage of gems valued for their brilliance and clarity.
Tanzanite: A Modern Marvel In stark contrast to the ancient pedigree of turquoise and zircon, tanzanite is a recent addition to the gemological world. Its official recognition as a December birthstone occurred in 2002, when the American Gem Trade Association (AGTA) added it to the modern birthstone list. This update, which began in 1912 with the American National Retail Jeweler's Association, reflects an evolving tradition that seeks to highlight rare gems and provide more options. Tanzanite's discovery is a 20th-century story, and its rapid rise to prominence is evidenced by its appearance on modern red carpets, worn by celebrities like Cate Blanchett in earrings that showcase its velvety blue hues. Its inclusion as a modern birthstone signifies a bridge between traditional gemology and contemporary trends.
Geological Formation and Sources
The formation and mining locations of these three gemstones are as diverse as their histories, ranging from the chemical alteration of volcanic rock to alluvial deposits and singular geological formations.
Turquoise Turquoise is not formed from typical magma or high-pressure conditions but through a secondary geological process. It is created by groundwater containing copper that seeps into bedrock. Over time, reactions with other minerals form an opaque stone in stunning shades of blues and greens. The dark lines and shapes seen in turquoise are derived from the surrounding rock, known as the matrix. Major source countries for turquoise include Iran, the United States (particularly the Southwest), Tibet, and India. Each region produces turquoise with distinct color characteristics and matrix patterns, influenced by the local geology.
Zircon The provided sources do not detail the specific geological formation or primary mining locations for blue zircon. However, zircon as a mineral is known to be one of the oldest on Earth, found in many igneous and metamorphic rocks. Its presence in antique jewelry suggests historical sources, but the chunks lack explicit information on modern mining regions for the blue variety used in birthstone jewelry.
Tanzanite Tanzanite's origin story is geologically unique. It is found in only one location on Earth: the Merelani Hills of northern Tanzania, near the base of Mount Kilimanjaro. This single-source locality makes it exceptionally rare. The gem is a variety of the mineral zoisite and is formed through a complex process involving heat and pressure affecting the parent rock. Its discovery in the 1960s and subsequent mining have made it a celebrated gem of the modern era.
Gemological Properties
Understanding the physical and chemical properties of these gems is essential for appreciation, care, and identification.
| Gemstone | Mineral Group | Chemical Composition | Hardness (Mohs Scale) | Typical Colors | Clarity & Characteristics |
|---|---|---|---|---|---|
| Turquoise | Phosphate | Hydrated copper aluminum phosphate | 5 – 6 | Sky blue, greenish-blue | Opaque; dark matrix inclusions from host rock. |
| Tanzanite | Zoisite (Sorosilicate) | Calcium aluminum hydroxyl sorosilicate | 6.5 – 7 | Blue-violet | Typically transparent to translucent; can show pleochroism (showing different colors from different angles). |
| Zircon | Zircon (Silicate) | Zirconium silicate (ZrSiO₄) | 6.5 – 7.5 | Blue (treated) | Typically transparent; high refractive index gives it exceptional brilliance and fire. |
Turquoise Turquoise belongs to the phosphate mineral group. Its hardness on the Mohs scale ranges from 5 to 6, making it relatively soft compared to many gemstones. This softness contributes to its use in carvings and cabochons but also means it is susceptible to scratching and requires careful handling. The colors range from sky blue to greenish-blue, influenced by the amount of copper (blue) and iron (green) in its composition. Its opacity is a defining trait, and the presence of a dark matrix—the host rock material—adds to its unique character. Major origin countries are Iran, the United States, Tibet, and India.
Tanzanite Tanzanite is a variety of the mineral zoisite, a sorosilicate. It has a hardness of 6.5 to 7 on the Mohs scale, making it durable enough for most jewelry settings. Its most prized color is a vivid blue-violet, which is the result of heat treatment applied to the naturally brownish material mined from Tanzania. This treatment is standard and permanent. Tanzanite is typically transparent to translucent and can exhibit strong pleochroism, displaying different shades of blue and violet from different crystal directions.
Zircon Zircon is a zirconium silicate and should not be confused with the synthetic cubic zirconia. Natural zircon has a hardness of 6.5 to 7.5, making it a durable gemstone suitable for jewelry. The blue zircon used as a birthstone is typically the result of heat treatment applied to brown zircon crystals. Zircon is known for its high refractive index and strong dispersion (fire), which gives it exceptional brilliance, often compared to that of diamond. The provided sources note its use in antique Victorian pieces, set in gold to highlight this fiery sparkle.
Symbolism and Metaphysical Beliefs
The symbolic meanings attributed to the December birthstones are rich and varied, reflecting their historical roles and the traits associated with their corresponding zodiac signs.
General Symbolism for December Collectively, the December birthstones—Turquoise, Tanzanite, and Zircon—are associated with serenity, wisdom, protection, and calmness. Their cool blue and green hues are said to promote emotional balance and inner peace, making them ideal for individuals seeking stability and clarity.
Zodiac-Specific Associations The two zodiac signs for December, Sagittarius and Capricorn, have specific gemstone connections that align with their astrological profiles.
- Sagittarius (Nov 22 – Dec 21): This fire sign, known for its optimism, adventure-seeking nature, and love of travel, is strongly linked to Turquoise. Sources indicate that Turquoise provides protective energy during travels and enhances luck and optimism. Some sources also mention Topaz as a primary stone for Sagittarius, with Turquoise as a secondary stone. Other crystals suggested for Sagittarius include snowflake obsidian, sodalite, clear quartz, citrine, and tiger's eye to amplify their adventurous qualities.
- Capricorn (Dec 22 – Jan 19): This earth sign, characterized by discipline, ambition, and self-sufficiency, is traditionally associated with Ruby as its primary birthstone. However, among the December gems, Zircon is specifically tied to Capricorn for its grounding energy, which helps clear mental blocks and enhance focus. Some sources also link Tanzanite's transformational energy to Capricorn's ambitious nature. For Capricorns, other supportive crystals include garnet, fluorite, smoky quartz, onyx, and azurite.
Individual Gemstone Meanings * Turquoise: As a sacred stone in many cultures, its symbolism is deeply rooted in protection, friendship, and good fortune. It was believed to be a conduit for truth and a shield against negative forces. * Tanzanite: Its modern symbolism is often linked to transformation and spiritual awakening, aligning with its recent discovery and vibrant, otherworldly color. It is seen as a stone of new beginnings. * Zircon: Its brilliant sparkle symbolizes purity, prosperity, and wisdom. Historically, it was believed to aid in sleep and promote prosperity and honor.
Care and Cleaning
Proper maintenance is crucial to preserve the beauty and integrity of these gemstones, especially given their varying hardness and characteristics.
General Care for December Birthstones To keep December birthstone jewelry sparkling, gentle cleaning is recommended. A common and safe method is to use lukewarm soapy water with a soft brush, followed by patting dry with a microfiber cloth. Ultrasonic cleaners and steam cleaners should be avoided, as they can damage certain gemstones.
Specific Care Considerations * Turquoise (Mohs 5-6): Due to its relative softness and porosity, turquoise requires the most care. It can be scratched by harder materials and may be damaged by chemicals, cosmetics, and even prolonged exposure to sunlight, which can cause fading. It is best to put on turquoise jewelry after applying lotions and perfumes and to store it separately from other jewelry to prevent scratches. * Tanzanite (Mohs 6.5-7): While more durable than turquoise, tanzanite can still be scratched. It has perfect cleavage in one direction, meaning it can split if struck with force. It should be protected from hard blows and stored carefully. * Zircon (Mohs 6.5-7.5): Zircon is a durable gem, but it can be brittle due to its crystal structure. It is susceptible to chipping if hit hard, so protective settings are advisable for rings. It is generally stable under normal conditions but can be damaged by extreme heat or sudden temperature changes.
Conclusion
The December birthstones—Turquoise, Tanzanite, and Zircon—offer a captivating blend of ancient heritage, modern discovery, and geological rarity. Turquoise carries the weight of millennia, serving as a protective talisman across empires and cultures. Tanzanite represents the thrill of a new find, a gem born from a single location that has captured the modern imagination with its unique blue-violet hue. Zircon, with its diamond-like fire, bridges the gap between antique elegance and contemporary brilliance. Together, they provide a spectrum of choices for December-born individuals, each stone resonating with different aspects of the Sagittarius and Capricorn personalities. Whether chosen for its historical lore, metaphysical properties, or sheer visual beauty, this cool-hued trio stands as a testament to the enduring allure of gemstones, connecting the wearer to a deep history of earth, culture, and sky.