For individuals born on December 22nd, the birthstone selection is uniquely distinguished by a trio of gemstones united by their captivating blue hues: tanzanite, turquoise, and zircon. This combination, officially recognized for this specific date, offers a remarkable spectrum of color, from the vibrant violet-blue of tanzanite to the sky-blue of turquoise and the brilliant fire of blue zircon. Each stone possesses a distinct geological history, cultural legacy, and set of gemological properties, making this triad one of the most diverse and meaningful in the modern birthstone calendar. The month of December itself is one of only two months to feature three official birthstones, a reflection of the season's symbolic connection to the cool, serene tones of winter skies and icy landscapes. This article provides a comprehensive exploration of these three gems, detailing their origins, physical characteristics, historical significance, and practical care, offering gemstone enthusiasts, jewelry buyers, and students of gemology a deeper understanding of the December 22nd birthstones.
History and Lore
The tradition of assigning gemstones to specific dates is ancient, with foundational references appearing in the biblical Book of Exodus. The text describes the High Priest’s breastplate, adorned with twelve stones representing the twelve tribes of Israel. Over time, these stones became associated with the months of the year and zodiac signs, forming the basis of the modern birthstone calendar. The evolution of this calendar has been ongoing, with formal lists established by organizations like the National Association of Jewelers in the early 20th century, later updated to include additional stones for greater variety and personal choice.
December stands out for having three officially recognized birthstones: tanzanite, turquoise, and zircon. This multiplicity allows for a range of colors, prices, and personal meanings, catering to diverse tastes. For December 22nd, this triad is specifically highlighted, supported by historical usage and cultural significance. The inclusion of multiple stones for a single month reflects the rich symbolism of December and the availability of gemstones in blue tones, which resonate with the cold, serene imagery of winter.
Turquoise: The Ancient Protector
Turquoise has a history spanning thousands of years, revered across numerous ancient civilizations. It was used by Egyptians, Persians, and Native American cultures, primarily associated with protection, healing, and prosperity. Its enduring popularity is a testament to its deep-rooted cultural significance and timeless appeal. As one of the oldest known gemstones in human history, turquoise carries a legacy of spiritual and protective attributes that have been passed down through generations.
Zircon: The Mistaken Brilliance
Zircon, particularly in its blue variety, has been known since antiquity. Its exceptional brilliance and clarity have often led to it being mistaken for other gemstones, including diamond and sapphire. Historically, zircon has been prized for its refractive fire, making it a standout gemstone in both historical and contemporary settings. Its association with truth and spiritual awakening adds a layer of metaphysical depth to its physical beauty.
Tanzanite: The Modern Marvel
In contrast to the ancient stones, tanzanite is a relatively new discovery. Found only in Tanzania in the 1960s, it quickly gained popularity in the jewelry world due to its vivid blue-to-violet color and remarkable rarity. Its limited geographical source has contributed to its status as a symbol of transformation and success. Despite its recent introduction to the gemstone market, tanzanite has secured its place as a modern classic, valued for its unique pleochroic properties and stunning visual appeal.
Geological Formation and Sources
The three December 22nd birthstones originate from vastly different geological environments and are sourced from distinct regions of the world.
Turquoise: A Hydrated Phosphate Mineral
Turquoise is a hydrated phosphate of copper and aluminum, forming in arid regions where acidic, copper-rich water percolates through rocks containing aluminum and phosphorus. This process can take millions of years, resulting in veins and nodules of turquoise. Major sources include the United States (particularly Arizona and New Mexico), Iran, and China. The quality and color of turquoise are heavily influenced by its matrix (the host rock) and the specific mineral content during its formation.
Zircon: A Zirconium Silicate
Zircon is a zirconium silicate mineral that forms in igneous and metamorphic rocks. It is one of the oldest minerals on Earth, with some zircon crystals dating back billions of years. The blue variety of zircon is typically produced by heat-treating brown zircon crystals to remove impurities and enhance their color. Primary sources for gem-quality zircon include Sri Lanka, Cambodia, Myanmar, and Australia. The heat treatment is a standard industry practice and is accepted for enhancing the gem's color, provided it is disclosed.
Tanzanite: A Unique Silicate Mineral
Tanzanite is a variety of the mineral zoisite, specifically the blue to violet-blue form colored by trace amounts of vanadium. It is found exclusively in the Merelani Hills of northern Tanzania, near Mount Kilimanjaro. The gemstone's formation is linked to a specific geological event that occurred approximately 585 million years ago, when intense heat and pressure transformed existing zoisite crystals. The limited geographic occurrence of tanzanite makes it significantly rarer than diamond, contributing to its value and desirability. Its discovery in the 1960s and subsequent introduction to the global market marked a significant event in modern gemology.
Gemological Properties
Understanding the physical and chemical properties of these gemstones is essential for their identification, valuation, and care. The following table summarizes key gemological data for tanzanite, turquoise, and zircon, based on established gemological standards.
| Property | Tanzanite | Turquoise | Zircon (Blue) |
|---|---|---|---|
| Chemical Formula | Ca₂Al₃(SiO₄)₃(OH) | CuAl₆(PO₄)₄(OH)₈·4H₂O | ZrSiO₄ |
| Crystal System | Orthorhombic | Triclinic | Tetragonal |
| Mohs Hardness | 6.5 - 7 | 5 - 6 (often softer due to porosity) | 6.5 - 7.5 |
| Refractive Index | 1.691 - 1.700 | 1.610 - 1.650 | 1.92 - 2.01 |
| Specific Gravity | 3.35 | 2.60 - 2.90 | 4.6 - 4.7 |
| Key Features | Strong trichroism (blue, violet, burgundy); often heat-treated. | Often porous; color can fade with prolonged sun exposure. | High refractive index and dispersion ("fire"); often heat-treated for color. |
Tanzanite
Tanzanite's most defining characteristic is its strong trichroism—the ability to display three different colors when viewed from different crystal directions: typically blue, violet, and burgundy. This property is due to its crystal structure and the presence of vanadium. Most tanzanite on the market has been heat-treated to enhance its blue color and reduce the visibility of brownish or yellowish tints. With a hardness of 6.5 to 7 on the Mohs scale, it is durable enough for most jewelry but requires care to avoid scratches and impacts.
Turquoise
Turquoise is an opaque gemstone, meaning it is not transparent. Its color ranges from sky blue to blue-green, influenced by the amount of copper (blue) and iron (green) in its composition. Turquoise is relatively soft, with a Mohs hardness of 5 to 6, and is often porous. This porosity makes it susceptible to absorbing oils, chemicals, and cosmetics, which can alter its color over time. Many turquoise pieces are stabilized with resins or waxes to improve durability and color consistency.
Zircon
Blue zircon is renowned for its exceptional brilliance and fire, rivaling that of diamond. Its high refractive index (1.92-2.01) and strong dispersion (0.039) give it a sparkling quality. Zircon has a hardness of 6.5 to 7.5, making it suitable for jewelry, though it can be brittle and prone to chipping if struck. Natural blue zircon is rare; most blue zircon in the market is produced by heat-treating brown zircon crystals. The heat treatment is stable and does not fade over time. Zircon is also one of the few gemstones that can display metamictization, where its crystal structure becomes amorphous due to the natural radioactive decay of uranium and thorium impurities, which can affect its stability.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, each of the December 22nd birthstones carries a rich tapestry of symbolic meanings and metaphysical beliefs, often rooted in ancient traditions and modern interpretations.
Tanzanite: Transformation and Intuition
Tanzanite is often associated with transformation, spiritual awakening, and heightened intuition. Its discovery in the 20th century links it to modernity and progress, yet its deep blue hues evoke a sense of cosmic connection. In metaphysical circles, tanzanite is believed to facilitate communication with higher spiritual realms and to encourage the wearer to embrace change and personal growth. Its trichroic nature is sometimes interpreted as representing the union of mind, body, and spirit.
Turquoise: Protection and Healing
Turquoise is one of the most universally symbolic gemstones, historically regarded as a protective talisman. It was worn by ancient warriors and travelers to ward off harm and negative energy. In many cultures, turquoise is also linked to healing, balance, and emotional stability. For example, in Native American traditions, it is considered a sacred stone that connects the wearer to the earth and sky. Its color, reminiscent of water and sky, reinforces its association with tranquility and clarity.
Zircon: Truth and Spiritual Awakening
Zircon, particularly blue zircon, is symbolically tied to truth, purity, and spiritual awakening. Its brilliance is seen as a metaphor for inner light and clarity of thought. Historically, zircon was believed to promote restful sleep, ward off nightmares, and attract prosperity. In some traditions, it is also considered a stone of grounding and protection, helping the wearer navigate life’s challenges with wisdom and integrity. The heat-treated blue variety carries these same associations, with its enhanced color amplifying its perceived energetic properties.
Care and Cleaning
Proper care is essential to maintain the beauty and longevity of these gemstones, given their differing physical properties.
Tanzanite Care
With a hardness of 6.5 to 7, tanzanite is relatively durable but should be protected from sharp blows and abrasive materials. It is best cleaned with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning, as these can cause fractures or damage due to the stone’s internal characteristics. Store tanzanite jewelry separately to prevent scratching by harder gems like diamonds or sapphires.
Turquoise Care
Due to its porosity and lower hardness (5-6), turquoise requires gentle handling. It should be kept away from chemicals, cosmetics, perfumes, and prolonged exposure to sunlight, which can cause fading. Clean turquoise with a soft, dry cloth; avoid soaking it in water or using harsh cleaning agents. For stabilized turquoise, a slightly damp cloth may be used, but it should be dried immediately. Store turquoise in a cool, dark place to preserve its color.
Zircon Care
Zircon’s hardness (6.5-7.5) makes it suitable for everyday wear, but its brittleness means it should be protected from hard impacts. Clean zircon with warm, soapy water and a soft brush. Avoid ultrasonic cleaners, as vibrations can cause fractures in stones with inclusions or metamictization. Zircon can be sensitive to heat, so keep it away from high temperatures and sudden temperature changes. Store it in a fabric-lined jewelry box to prevent scratching.
Conclusion
The birthstones for December 22nd—tanzanite, turquoise, and zircon—form a compelling triad that bridges ancient history and modern discovery. From the protective legacy of turquoise and the timeless brilliance of zircon to the transformative allure of tanzanite, each gemstone offers a unique combination of aesthetic appeal, cultural significance, and gemological intrigue. Their collective blue hues resonate with the serene and reflective qualities of December, providing a meaningful connection to the natural world and human heritage. For those born on this date, this selection not only offers a beautiful array of choices but also a rich narrative of transformation, protection, and truth, encapsulated within the enduring beauty of precious stone.