December is a month of reflection and celebration, marked by a unique and vibrant array of birthstones that capture the cool tones of winter and the deep hues of twilight. Unlike most months, which are typically associated with a single gem, December is celebrated with a diverse palette of blue and violet stones: Turquoise, Tanzanite, Zircon, and, in modern interpretations, Blue Topaz. This multiplicity offers those born in December a remarkable range of choices, each with its own distinct history, geological origin, and symbolic significance. From the ancient, opaque sky-blue of Turquoise to the electric violet-blue of Tanzanite, the fiery brilliance of Zircon, and the serene icy blue of Topaz, these gemstones provide a spectrum of color and character. This article explores the rich tapestry of December's birthstones, delving into their historical lore, geological formation, gemological properties, and care, providing a comprehensive guide for enthusiasts, collectors, and anyone seeking to understand the gemstones of the twelfth month.
Historical Lore and the Path to Modern Birthstones
The tradition of birthstones is ancient, with roots tracing back to civilizations that believed in the mystical and healing properties of specific gemstones. The concept is often linked to the Biblical Breastplate of Aaron, which featured twelve stones representing the twelve tribes of Israel. Over time, these stones became associated with the twelve months of the year. However, the list of birthstones for December has evolved significantly, reflecting both historical precedence and modern commercial and aesthetic preferences.
Turquoise stands as the oldest and most traditional of December's stones. Its use dates back millennia, adorning the pharaohs of ancient Egypt and being carved by Chinese artisans over 3,000 years ago. The stone has been a constant in many cultures, from the Persian empires to the Native American tribes of the American Southwest. For centuries, it was the primary birthstone for December, revered for its protective qualities. The Apache believed turquoise could be found by following a rainbow to its end, and Hindu mystics associated it with wealth, claiming that seeing a turquoise after beholding the new moon ensured fantastic fortune. Its significance was so profound that it was thought to change color to warn the wearer of danger or illness and to break into pieces at the approach of disaster.
Zircon, the other traditional December birthstone, has a history nearly as long. For centuries, it was a popular gem in Europe, particularly during the Victorian era, where it was prized for its brilliance and fire, often mistaken for diamond. The confusion between zircon and cubic zirconia (a synthetic diamond simulant) has sometimes tarnished its reputation, but natural zircon is one of the oldest minerals on Earth, with deposits dating back billions of years. It was believed to promote wisdom, honor, and purity, and was thought to aid in sleep and bring prosperity.
In the 20th century, the list expanded to include Tanzanite. Discovered in the Merelani Hills of Tanzania in 1967, this gemstone is a relative newcomer to the gemological world. Its introduction was met with excitement due to its unique, intense violet-blue color, which is unlike any other naturally occurring gem. Tiffany & Co. recognized its potential and launched a major marketing campaign in 1968, positioning it as a precious gemstone. Its modern status as a December birthstone is largely a result of this successful introduction and its alignment with the month's cool color palette.
Blue Topaz is a more recent addition, often categorized as a modern alternative birthstone for December, particularly in the United States. While the name "Topaz" has ancient origins—stemming from the Greek "Topazios," an island in the Red Sea where the stone was supposedly found (though the island's stones were later identified as Peridot)—the vivid blue topaz available today is almost always the result of treating colorless or pale topaz through irradiation and heat. Its popularity surged in the late 20th century as a durable and affordable blue gemstone, filling a market demand for a more accessible December option.
The modern list of birthstones was formalized by organizations like the American Gem Society (AGS) and the Gemological Institute of America (GIA). The GIA, a leading authority in gemology, recognizes Turquoise, Tanzanite, and Zircon as the official December birthstones. This trio offers a range from opaque to transparent, from historic to modern, and from softer to harder stones, providing a comprehensive selection for December-born individuals.
Geological Formation and Sources
Understanding the origin of these gems enhances their appreciation. Each stone forms under distinct geological conditions, leading to their unique characteristics and geographic sources.
Turquoise is a secondary mineral that forms in arid regions where acidic, copper-rich water percolates through rocks containing aluminum and phosphorus. Over millions of years, these minerals precipitate and fill cavities, veins, and fractures, creating the turquoise deposits. It is typically found in massive, nodular, or vein-like forms. Major sources include: * Iran (Persia): Historically the most prized source, producing the classic "sky blue" turquoise with minimal matrix. * United States: The Southwestern states, particularly Arizona and New Mexico, are significant producers. American turquoise often has a greenish-blue hue and is frequently associated with a brown or black matrix (the host rock). * Tibet and China: Known for stones with a distinctive greenish-blue color and matrix patterns. * Egypt: The Sinai Peninsula was a major source for ancient Egyptians.
Zircon is a zirconium silicate (ZrSiO₄) that crystallizes from magma during the final stages of cooling. It is a common accessory mineral in igneous rocks like granite and syenite. Because of its hardness and chemical stability, it is also a common detrital mineral in sedimentary sands. Major sources for gem-quality zircon include: * Sri Lanka: A historic source for brown, yellow, and blue zircon. * Cambodia: Known for producing high-quality, heat-treated blue zircon. * Australia: The source of the famous "Mudgate" zircon, which is often brown and heat-treated to blue. * Norway and Myanmar: Also contribute to the global supply.
Tanzanite is a variety of the mineral zoisite. It is found exclusively in the Merelani Hills of northern Tanzania, a small area of just a few square kilometers near Mount Kilimanjaro. This geographical singularity makes it one of the rarest gemstones in the world. It forms through a process of metamorphism, where heat and pressure from tectonic activity altered existing minerals. Its vibrant color is caused by trace amounts of vanadium within its crystal structure. The color is often unstable in its natural state and is typically stabilized through a gentle heating process to achieve the desirable violet-blue hue.
Blue Topaz is a variety of the topaz mineral, which is a fluorine aluminum silicate. While topaz crystals can be found in pegmatites and hydrothermal veins, the gem-quality material used for blue topaz is often sourced from large, colorless crystals mined in Brazil, Sri Lanka, Nigeria, and China. The vivid blue color is not typically found in nature; it is achieved through irradiation (exposing the stone to controlled radiation) followed by heat treatment to shift the color from a pale yellow or brown to a stable, even blue. This process is standard in the industry and is disclosed by reputable sellers.
Gemological Properties: A Scientific Overview
The physical and chemical properties of a gemstone determine its durability, appearance, and value. The December birthstones vary widely in these characteristics, which is a key reason for their diverse uses in jewelry.
| Gemstone | Chemical Composition | Crystal System | Mohs Hardness | Refractive Index | Typical Treatments | Notable Characteristics |
|---|---|---|---|---|---|---|
| Turquoise | Hydrated copper aluminum phosphate | Triclinic | 5 - 6 | ~1.61 | Stabilization (waxing, impregnation) | Opaque to semi-translucent; often has matrix; porous. |
| Zircon | Zirconium silicate (ZrSiO₄) | Tetragonal | 6.5 - 7.5 | 1.92 - 1.98 | Heat treatment (to achieve blue) | High brilliance and fire; can be brittle. |
| Tanzanite | Calcium aluminum hydroxyl silicate (Zoisite) | Orthorhombic | 6 - 7 | 1.69 - 1.70 | Heat treatment (to stabilize color) | Strong trichroism (blue, violet, burgundy). |
| Blue Topaz | Aluminum fluorine hydroxyl silicate | Orthorhombic | 8 | 1.61 - 1.63 | Irradiation and heat treatment | Excellent durability; color is almost always treated. |
Turquoise is a relatively soft and porous stone. Its hardness of 5 to 6 on the Mohs scale means it can be scratched by harder materials. Its porosity makes it susceptible to chemicals, cosmetics, and even skin oils, which can cause discoloration. For this reason, most turquoise on the market is stabilized—impregnated with a clear resin or wax to improve its durability, color, and polish. Natural, untreated turquoise is rare and highly valued, especially in the gem and jewelry trade.
Zircon is one of the hardest natural gemstones, ranking just below topaz and corundum (ruby/sapphire). Its high refractive index gives it a brilliance and fire that can rival diamond, making it a dazzling gemstone. However, it is also brittle and can be prone to chipping if struck hard, so it requires protective settings in jewelry, especially for rings. The most valued blue zircon is a medium to medium-dark blue with high clarity.
Tanzanite has a hardness of 6 to 7, making it suitable for jewelry but requiring care. It is known for its strong pleochroism, displaying different colors (blue, violet, and reddish-brown) when viewed from different angles. The finest tanzanite exhibits a rich, saturated violet-blue color with minimal brownish tints. Its rarity and unique color make it a prized gem for collectors and jewelry designers.
Blue Topaz is the hardest and most durable of the December stones, with a Mohs hardness of 8. This makes it an excellent choice for everyday jewelry, such as rings and bracelets, where it can withstand daily wear and tear. Its clarity is typically high, and the treated blue color is stable and permanent. The most popular shades are "Swiss Blue" (a bright, medium blue) and "London Blue" (a deep, saturated blue).
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, these gemstones are steeped in symbolism and metaphysical lore, which has been a driving force in their popularity for centuries.
Turquoise is universally recognized as a stone of protection, healing, and friendship. It has been called the "sky stone" and is believed to connect the wearer to the heavens. Its traditional significance includes good fortune, peace of mind, and the warding off of negative energy. In many cultures, it is a talisman for travelers, ensuring a safe journey. Its association with truth and wisdom is also prominent, making it a stone for those seeking clarity in communication.
Zircon is associated with wisdom, honor, and purity. It is believed to promote spiritual growth, enhance self-confidence, and bring prosperity. Historically, it was thought to aid in sleep and protect against nightmares. Its brilliant fire is said to symbolize the light of the spirit and the clarity of thought. For those born in December, zircon is thought to bring balance and stability, helping to ground the wearer while encouraging intellectual pursuits.
Tanzanite, as a modern gem, has developed its own set of metaphysical attributes. It is often linked to transformation, intuition, and new beginnings. Its discovery in the 20th century coincided with an era of great change, and it is seen as a stone that can facilitate spiritual awakening and higher consciousness. Its calming violet-blue color is believed to soothe anxiety and promote a sense of peace and mindfulness. Some believe it opens the gateway to the higher realms of thought and creativity.
Blue Topaz is considered a stone of calm, communication, and truth. Its serene blue color is associated with tranquility and emotional balance. It is believed to help express one's thoughts and feelings clearly and honestly. In metaphysical circles, it is thought to aid in meditation, enhance creativity, and attract good fortune. Its durability symbolizes strength and resilience, making it a stone for those who wish to overcome challenges with grace and clarity.
Care and Cleaning: Preserving the Beauty
Proper care is essential to maintain the beauty and longevity of any gemstone jewelry. Due to their varying hardness and chemical stability, the December birthstones require different approaches to cleaning and storage.
Turquoise is the most delicate of the group. It should be cleaned only with warm, soapy water and a soft cloth. Avoid all chemicals, including household cleaners, cosmetics, and perfumes, as they can penetrate the stone and cause permanent discoloration or damage to the stabilization treatment. It is also sensitive to prolonged exposure to water and heat, which can weaken the stone. Store turquoise jewelry separately to prevent scratching by harder gems.
Zircon is relatively hard but brittle. It can be cleaned with warm, soapy water and a soft brush. However, it should be kept away from sharp blows and extreme temperature changes, which can cause fractures. Avoid ultrasonic cleaners and steam cleaners, as the vibrations and heat can damage the stone, especially if it has been heat-treated. Store it in a soft cloth to protect its facets from chipping.
Tanzanite requires gentle handling. Clean it with warm, soapy water and a soft brush. Avoid ultrasonic and steam cleaners, as the vibrations and heat can cause the stone to fracture. Due to its relative softness and cleavage, it is best suited for earrings, pendants, and occasional-wear rings. When setting tanzanite, jewelers often use protective settings to minimize the risk of impact.
Blue Topaz is the most durable of the December stones and can be cleaned with standard methods: warm, soapy water, a soft brush, and even an ultrasonic cleaner (for stones without fractures). However, it is still susceptible to sharp impacts, which can cause chipping, so it should be handled with care. Its treated color is stable and will not fade with normal cleaning or exposure to light.
For all gemstone jewelry, it is a good practice to store pieces separately in a fabric-lined box to prevent scratches and damage. Regular professional inspections by a jeweler can ensure that settings are secure and the stones are in good condition.
Conclusion
The birthstones of December—Turquoise, Tanzanite, Zircon, and Blue Topaz—offer a remarkable diversity that reflects the month's own character: reflective, celebratory, and rich in history. From the ancient, protective talisman of Turquoise to the rare, transformative beauty of Tanzanite, the brilliant, wise fire of Zircon, and the serene, durable blue of Topaz, each stone provides a unique connection to the natural world and human culture. Their varied origins, from the arid deserts of Iran to the single, precious mine in Tanzania, tell stories of geological time and human endeavor. Their symbolic meanings, from protection and wisdom to transformation and truth, provide layers of significance beyond their physical beauty. By understanding their histories, properties, and care requirements, one can fully appreciate why these gems have been cherished for millennia and continue to be the perfect representation for those born in the final month of the year.