The month of December holds a unique distinction in the gemological calendar: it is the only month officially represented by three distinct traditional birthstones. While many months have seen their birthstone lists expand over time to include alternative options, December is specifically associated with the vibrant Turquoise, the captivating Tanzanite, and the sparkling Zircon. This trio of gems offers a diverse array of choices for those born in the final month of the year, each possessing a unique allure, a fascinating history, and a distinct set of properties. From the ancient, sky-blue talismans of antiquity to the modern discovery of a singular violet-blue gem, the December birthstones represent a rich tapestry of geological wonder and cultural significance.
The existence of three birthstones for December is not a matter of chance or mere preference; it reflects the evolving nature of the birthstone tradition itself. The American Gem Trade Association (AGTA) officially recognizes these three gems, acknowledging both their historical legacy and their contemporary appeal. This guide will explore the intricate details of each of these remarkable stones, delving into their geological origins, their journey through history, their specific gemological characteristics, and the symbolic meanings that have been ascribed to them across various cultures. By examining Turquoise, Tanzanite, and Zircon individually, we can appreciate the distinct qualities that make each a worthy and celebrated birthstone for December.
Turquoise: The Ancient Sky Stone
Turquoise stands as the most ancient and historically significant of the December birthstones. Its name, derived from the French "pierre tourques" or "Turkish stone," hints at its introduction to Europe via the Turkish Ottoman Empire from its primary source in the Persian Gulf region. However, the history of Turquoise extends far deeper, spanning continents and millennia. It is a mineral recognized for its unique and captivating color, which ranges from the most prized "robin's egg blue" to various shades of sky blue and greenish-blue. This coloration is due to the presence of copper within its chemical structure.
History and Lore
The allure of Turquoise is deeply embedded in ancient civilizations. The provided sources indicate that its history dates back to the ancient Egyptians, who regarded it as a sacred stone. It was used extensively in jewelry, amulets, and burial masks, symbolizing protection and connection to the divine. The ancient Persians also held Turquoise in high esteem, believing it offered protection from unnatural death and would change its color to warn its wearer of impending danger. This protective quality has been a consistent theme throughout its history, making it a popular talisman for warriors, travelers, and those seeking safe passage. Its use as a symbol of wealth and good fortune has been documented across numerous cultures, solidifying its status as a stone of protection and positivity.
Geological Formation and Sources
Turquoise is a secondary mineral that forms when acidic, copper-rich water percolates through pre-existing rocks containing aluminum and phosphorus. This process occurs in arid regions, and as the water evaporates, it leaves behind deposits of Turquoise in the host rock. This formation process explains why major Turquoise deposits are found in some of the world's driest climates. Historically, the finest Turquoise came from the Persian Gulf, known for its distinct, pure blue color and often a matrix of dark host rock. Today, significant sources include the Southwestern United States (particularly Arizona and New Mexico), China, and Egypt. The specific geology of each region imparts unique characteristics to the stone, such as the famous "spiderweb" matrix patterns found in many American specimens.
Gemological Properties
Turquoise is an opaque宝石 with a distinctive, waxy to vitreous luster. Its chemical composition is a hydrated phosphate of copper and aluminum, with the formula CuAl₆(PO₄)₄(OH)₈·4H₂O. On the Mohs scale of hardness, Turquoise ranks between 5 and 6, making it a relatively soft gemstone that requires careful handling. This porosity also means it can be susceptible to discoloration from chemicals, lotions, and even the oils in human skin. Consequently, many Turquoise stones are stabilized or treated with wax or resin to enhance their durability and color. Its specific gravity typically ranges from 2.60 to 2.90.
Symbolism and Metaphysical Beliefs
Beyond its protective history, Turquoise is strongly associated with calming and grounding energies. It is often seen as a steadying force, providing a sense of tranquility and peace to its wearer. Many believe it aids in detoxification and supports the immune system, connecting its blue-green hues to healing and well-being. In the context of Tarot, Turquoise is linked to "The Star" card, symbolizing hope, tranquility, and divine guidance, a fitting association for a stone long believed to be a conduit for celestial protection.
Care and Cleaning
Due to its porosity and moderate hardness, Turquoise requires specific care. It should be protected from prolonged exposure to direct sunlight, which can cause fading, and from harsh chemicals, including household cleaners and cosmetics. Cleaning should be done gently with warm, soapy water and a soft cloth. Avoid ultrasonic cleaners and steam cleaners, as the heat and vibrations can damage the stone. Storing Turquoise separately from harder gemstones will prevent it from being scratched.
Tanzanite: The Singular Violet-Blue
Tanzanite is a relative newcomer to the world of gemstones, yet it has rapidly ascended to become one of the most popular and sought-after blue gems. Its distinction lies in its unique color and its incredibly limited geographic origin, making it a true geological wonder.
History and Discovery
Unlike the ancient Turquoise, Tanzanite’s history is remarkably short. It was discovered only in the mid-20th century. The sources state that Tanzanite is a rare gem found exclusively in a single, small area of Northern Tanzania, near the majestic Mount Kilimanjaro. Its discovery is often attributed to a chance event in 1967, when a mass of blue crystals was found by a local herdsman. These crystals were soon identified as a variety of the mineral zoisite. The gem's potential was immediately recognized by Tiffany & Co., which introduced it to the world in 1968 and named it "Tanzanite" in honor of its exclusive origin. Its status as a birthstone was officially cemented in 2002 when the American Gem Trade Association added it to the list of stones for December, acknowledging its immense popularity and symbolic connection to the month.
Geological Formation and Sources
Tanzanite owes its existence to a unique and dramatic geological event. It is believed to have formed around 585 million years ago during the metamorphism of the metamorphic rocks of the Precambrian Mozambique Belt. The intense heat and pressure from tectonic plate shifts caused the original zoisite to recrystallize and incorporate trace elements like vanadium, which gave rise to its captivating blue-violet hue. This specific formation event is thought to have occurred in only one location on Earth, making Tanzanite’s occurrence extraordinarily rare. All commercially available Tanzanite is mined from a small area in the Merelani Hills of Northern Tanzania.
Gemological Properties
Tanzanite is a variety of the mineral zoisite and is known for its strong pleochroism, the property of displaying different colors when viewed from different crystal directions. A cut Tanzanite stone will typically show blue, violet, and sometimes burgundy hues depending on the viewing angle. Its chemical formula is Ca₂Al₃(SiO₄)₃(OH). It has a Mohs hardness of 6.5 to 7, making it somewhat more durable than Turquoise but still susceptible to chipping if struck with force. Most Tanzanite available in the market has been heat-treated to remove the brownish undertones and enhance its desirable blue color, a process that is considered stable and permanent.
Symbolism and Metaphysical Beliefs
Tanzanite is a stone of transformation, intuition, and spiritual growth. Its deep, shifting colors are said to reflect the process of moving into new chapters of life with clarity and purpose. It is believed to foster compassion and calmness, acting as a conduit for higher consciousness and spiritual awareness. In Tarot symbolism, Tanzanite resonates with "The Hierophant" card, which embodies wisdom, spiritual guidance, and the pursuit of higher knowledge. This association highlights its role as a stone for those seeking a deeper understanding of themselves and the universe.
Care and Cleaning
With a hardness of 6.5 to 7 and some cleavage, Tanzanite requires careful handling. It is not recommended for rings or other jewelry that is likely to receive daily knocks and abrasions. Pendants and earrings are safer settings. To clean Tanzanite, use warm, soapy water and a soft brush. As with Turquoise, it should be kept away from ultrasonic and steam cleaners, which can cause damage. Sudden temperature changes should also be avoided.
Zircon: The Sparkling Fire
Zircon is one of the oldest minerals on Earth, yet it is often confused with the synthetic cubic zirconia, a misconception that has unfairly overshadowed its natural beauty and significance. As a December birthstone, Zircon is prized for its exceptional brilliance and fire, rivaling that of diamond.
History and Lore
Zircon’s history is as ancient as the Earth itself. Geologically, it is a detrital mineral, meaning it survives the weathering of its parent rock and is deposited in sediments. This durability has allowed geologists to date some of the oldest rocks on Earth using Zircon crystals. In medieval Europe, Zircon was considered a protective stone, believed to promote honor, purity, and wisdom. It was also said to induce sleep and ward off evil spirits. Its name is thought to be derived from the Persian "zargun," meaning gold-colored, though Zircon occurs in a variety of colors.
Geological Formation and Sources
Zircon is a mineral belonging to the group of nesosilicates. It forms as an accessory mineral in igneous and metamorphic rocks, such as granite and gneiss. The primary sources for gem-quality Zircon include Thailand, Cambodia, Sri Lanka, and Australia. The blue varieties, which are most commonly associated with December, are typically created by heating brownish Zircon from certain localities, a process that is stable and enhances the stone's color.
Gemological Properties
Zircon is renowned for its high refractive index and strong dispersion, which give it exceptional brilliance and "fire." Its chemical formula is ZrSiO₄. On the Mohs scale, Zircon has a hardness of 6.5 to 7.5, making it a relatively durable gemstone, though it can be brittle due to its tetragonal crystal structure. It should be protected from hard blows, particularly in settings like rings. Zircon occurs in a wide spectrum of colors, but the blue variety, often marketed as "blue zircon," is the most popular for December. It is distinct from cubic zirconia, a synthetic diamond simulant, which is a completely different material.
Symbolism and Metaphysical Beliefs
Zircon is associated with clarity, wisdom, and a sense of balance. It is believed to sharpen the mind and enhance focus, making it a stone for scholars and those in pursuit of knowledge. Some traditions hold that Zircon promotes restful sleep and can attract prosperity and honor. Its brilliant sparkle is seen as a reflection of inner light and truth. In Tarot, Zircon connects with "The World" card, representing completion, accomplishment, and the fulfillment of a journey, a powerful symbol for the end of the year.
Care and Cleaning
Due to its brittleness, Zircon should be handled with care. It is best suited for pendants and earrings rather than rings that might experience daily impact. Cleaning can be done with warm, soapy water and a soft brush. While Zircon is generally stable, it is advisable to avoid sudden temperature changes and harsh chemicals. It is also susceptible to abrasion, so it should be stored carefully to prevent scratching by harder stones.
Comparative Overview
To better understand the distinct characteristics of the three traditional December birthstones, the following table summarizes their key gemological properties.
| Property | Turquoise | Tanzanite | Zircon |
|---|---|---|---|
| Mineral Species | Hydrated Copper Aluminum Phosphate | Variety of Zoisite | Zirconium Silicate |
| Chemical Formula | CuAl₆(PO₄)₄(OH)₈·4H₂O | Ca₂Al₃(SiO₄)₃(OH) | ZrSiO₄ |
| Hardness (Mohs) | 5 - 6 | 6.5 - 7 | 6.5 - 7.5 |
| Crystal System | Triclinic | Orthorhombic | Tetragonal |
| Typical Color | Sky blue to greenish-blue | Blue, violet-blue (pleochroic) | Colorless, blue, yellow-gold |
| Luster | Waxy to Vitreous | Vitreous | Adamantine to Vitreous |
| Transparency | Opaque | Transparent to Translucent | Transparent |
This comparison highlights the differences in hardness, which directly impacts durability and recommended use in jewelry. While Zircon is the hardest of the three, all three require a degree of care that differs from more robust gems like sapphire or diamond. Their chemical compositions and crystal systems are entirely different, underscoring their unique geological origins.
Care and Cleaning of December Birthstones
Proper care is essential to maintain the beauty and longevity of any gemstone. For the December birthstones, this is particularly important due to their varying levels of hardness and porosity.
- Turquoise: As the softest and most porous of the trio, Turquoise demands the most attention. It should be wiped clean with a soft, dry cloth after wear to remove oils and sweat. For a deeper clean, use lukewarm water with a tiny amount of mild soap, rinse thoroughly, and pat dry. Never use ultrasonic cleaners, steam cleaners, or harsh chemicals. Store it separately to avoid scratches.
- Tanzanite: With a moderate hardness and some cleavage, Tanzanite is sensitive to blows and temperature changes. Clean it with warm, soapy water and a soft brush. Avoid ultrasonic and steam cleaners. It is best kept in a padded jewelry box away from other stones.
- Zircon: Although Zircon is relatively hard, it is brittle and can be easily chipped if knocked against a hard surface. Clean it with warm, soapy water and a soft brush. Avoid ultrasonic cleaners (especially if the stone has been fracture-filled) and sudden temperature changes. Store it carefully to protect it from abrasion and impact.
Conclusion
The December birthstones—Turquoise, Tanzanite, and Zircon—offer a remarkable trifecta of beauty, history, and symbolism. Turquoise connects us to the ancient world, with its protective legacy and calming, earthy tones. Tanzanite, the modern marvel, speaks of transformation and the unique wonders of our planet, with its singular origin and captivating violet-blue hue. Zircon, the ancient sparkler, provides brilliant fire and is a symbol of wisdom and clarity. Together, they provide a rich palette of choices for those born in December, allowing for a personal connection based on individual taste, from the historic and grounding to the modern and visionary. Each stone, with its unique story and properties, is a testament to the diverse and wondrous creations of the geological world.