For individuals born in the final month of the year, the birthstone selection is unique and diverse. Unlike most months, which are assigned a single gem, December is associated with three official stones—Turquoise, Zircon, and Tanzanite—along with the popular alternative, Blue Topaz. This abundance offers a spectrum of blue hues, ranging from the soft, sky-blue of Turquoise to the vivid violet-blue of Tanzanite and the brilliant, clear blue of Zircon. These gemstones are united not only by their color, which reflects the winter season, but also by a rich tapestry of history, geological rarity, and symbolic meaning. The variety ensures that those born in December can select a stone that resonates with their personal style, budget, and the specific attributes they wish to embody, be it protection, wisdom, or transformation.
This article provides a comprehensive exploration of December’s birthstones. It will delve into the history and lore that elevated these gems to their esteemed status, examine the geological conditions that create their distinct colors, and detail the specific gemological properties that define them. Furthermore, it will discuss the metaphysical beliefs associated with each stone and provide practical advice for their care and maintenance, ensuring their beauty endures for generations.
History and Lore: The Journey to a Birthstone
The association of specific gemstones with calendar months has evolved over centuries, culminating in the modern lists used today. For December, this history is particularly layered, involving ancient traditions, commercial standardization, and the introduction of new discoveries.
The Ancient Roots of Turquoise
Turquoise is arguably the oldest and most historically significant of December’s birthstones. Its name is derived from the French phrase pierre turquoise, meaning "stone of Turkey," a reference to the trade routes through which the stone was brought to Europe from Turkish bazaars. This gem has been cherished for millennia, adorning the pharaohs and other rulers of ancient Egypt and being carved by Chinese artisans more than 3,000 years ago. Its importance extended across cultures; it played a vital role in the lives of Native Americans, with the Apache believing turquoise could be found by following a rainbow to its end. Historically, the stone was thought to possess potent powers, from guaranteeing health and good fortune to protecting the wearer from falls—a belief held from the 13th century onward. It was also believed to shatter in the presence of disaster, serving as a tangible warning to its owner.
The Modern Standardization of Birthstones
The formalization of birthstone lists began in the early 20th century. In 1912, the National Association of Jewelers (NAJ) sought to standardize the unofficial American birthstone list, combining historical customs with gemstones that were practical for the jewelry trade. This list has been updated several times to reflect new discoveries and changing tastes. In 1952, the Jewelry Industry Council of America added Zircon to December’s list, expanding the options for those born in the month. The most recent major addition came in 2002, when Tanzanite was officially added by the American Gem Trade Association (AGTA), recognizing its growing popularity and significance in the gem market.
The Rise of Blue Topaz
While not one of the three official stones listed by the Gemological Institute of America (GIA), Blue Topaz has emerged as a mainstream and popular alternative for December. Its inclusion in many modern jewelry guides reflects its widespread appeal, particularly due to its affordability and durability. The exact historical origin of blue topaz is obscure, but it has been found and used throughout history. Its modern prominence is largely due to the jewelry industry's ability to treat colorless topaz to achieve a deep, consistent blue, making it an accessible option for consumers. This expansion of options—Turquoise, Zircon, Tanzanite, and Blue Topaz—gives December-born individuals unparalleled choice in color, durability, and price.
Geological Formation and Global Sources
The distinct appearance of each December birthstone is a direct result of its unique geological formation and chemical composition. Each stone forms under specific conditions and is sourced from limited locations around the globe.
Turquoise: A Product of Water and Minerals
Turquoise is a secondary mineral that forms when water containing copper and aluminum seeps through pre-existing rock. This process occurs in arid regions, where the groundwater evaporates and leaves behind deposits of the turquoise mineral. The characteristic blue and green hues are directly caused by the presence of copper (which produces blue) and iron (which produces green). The dark veins and blotches often seen running through the stone are known as "matrix," which is the remnants of the host rock in which the turquoise formed. Major sources for high-quality turquoise include Iran, the United States (particularly Arizona and New Mexico), Tibet, and India.
Zircon: An Ancient Crystal
Zircon is one of the oldest minerals on Earth, with crystals found in Australia that date back over 4.4 billion years. It is a zirconium silicate that forms in the cracks and cavities of igneous and metamorphic rocks. While zircon occurs in a wide range of colors, the sky-blue variety is the one associated with December. This blue color is typically achieved through a heat treatment process, which can turn the common brown zircon into the desirable blue hue. While sources for zircon are widespread, including Sri Lanka, Australia, and Cambodia, the gem is known for its exceptional brilliance.
Tanzanite: A Geological Anomaly
Tanzanite is an exceptionally rare gemstone, found in only one location on the entire planet: the Merelani Hills of northern Tanzania, near the base of Mount Kilimanjaro. Its formation is a geological anomaly, requiring a unique combination of specific geological conditions that have only occurred in this small area. The stone is a variety of the mineral zoisite and gets its signature violet-blue color from trace amounts of vanadium. Due to its singular source, Tanzanite is considered up to a thousand times rarer than diamond, making its scarcity a key component of its value.
Blue Topaz: Abundant and Treated
Unlike the other December stones, natural blue topaz is rare. The vibrant blue stones seen in jewelry today are almost always the result of treating and irradiating colorless or pale blue topaz crystals. These crystals are often sourced from Brazil, Sri Lanka, Nigeria, and Mexico. The United States also has deposits, particularly in Texas, where blue topaz was designated the official state gem.
Gemological Properties: A Scientific Profile
Understanding the physical and chemical properties of these gemstones is crucial for both identification and care. The following table summarizes the key characteristics of the December birthstones based on available data.
| Gemstone | Mineral Group | Mohs Hardness | Chemical Formula | Key Characteristics |
|---|---|---|---|---|
| Turquoise | Phosphate | 5 – 6 | CuAl₆(PO₄)₄(OH)₈·4H₂O | Opaque, often with matrix (veins of host rock). Color ranges from sky blue to greenish-blue. |
| Zircon | Silicate | 6.5 – 7.5 | ZrSiO₄ | High refractive index gives it exceptional brilliance and fire. The blue variety is typically heat-treated. |
| Tanzanite | Zoisite | 6.5 – 7 | Ca₂Al₃(SiO₄)₃(OH) | Trichroic, showing blue, violet, and reddish hues depending on crystal orientation. |
| Blue Topaz | Silicate | 8 | Al₂SiO₄(F,OH) | Transparent and very durable. The deep blue color is almost always the result of irradiation and heat treatment. |
Turquoise
With a Mohs hardness of 5 to 6, turquoise is relatively soft compared to other gemstones. It is typically semi-translucent to opaque, and its color is determined by its copper and iron content. Its low hardness and porous nature make it susceptible to damage from chemicals, heat, and even the oils from human skin, which can alter its color over time.
Zircon
Zircon possesses a hardness of 6.5 to 7.5, making it reasonably durable for jewelry, though it can be brittle. Its most notable property is its high refractive index, which is superior to that of a diamond, giving it a brilliant sparkle and "fire" (the dispersion of light into spectral colors). The blue zircon used in jewelry is known for its bright, clear blue and high clarity.
Tanzanite
Tanzanite has a hardness of 6.5 to 7. It is prized for its strong pleochroism, a property known as trichroism, where the stone displays three different colors—violet-blue, dark blue, and reddish-purple—when viewed from different angles. Gem cutters must orient the crystal carefully to present the most desirable blue-violet color face-up. Most tanzanite is heated to a moderate temperature to remove brownish tones and enhance the vibrant blue and violet hues.
Blue Topaz
Blue topaz is the most durable of the December birthstones, with a hardness of 8 on the Mohs scale. This makes it an excellent choice for rings and jewelry worn daily. Its transparency and clarity allow for a brilliant cut that maximizes its sparkle. The color of commercial blue topaz ranges from pale "Sky Blue" to deep "London Blue," a result of different levels of treatment.
Symbolism and Metaphysical Beliefs
Across cultures and throughout history, December’s birthstones have been imbued with powerful meanings and attributed with special abilities.
- Turquoise is widely regarded as a stone of protection, good fortune, and friendship. It has been used as a talisman to ward off negative energy and bring peace and serenity to the wearer. Its association with health and good fortune is ancient, and it remains a symbol of wisdom and tranquility.
- Zircon is associated with clarity, wisdom, and a sense of balance. It is believed to help its wearer achieve spiritual growth and inner peace. Historically, it was also thought to promote honor and prosperity.
- Tanzanite, a more modern addition, symbolizes transformation and new beginnings. Its unique discovery story and striking color change have made it a stone for those undergoing significant life changes, encouraging a higher consciousness and a new perspective.
- Blue Topaz is often linked to calmness, clarity, and communication. It is believed to soothe the mind, reduce stress, promote truth and forgiveness, and aid in clear expression.
Care and Cleaning
Due to their varying levels of hardness and stability, the December birthstones require different approaches to care.
- Turquoise: As the softest and most porous of the group, turquoise requires gentle handling. It should be cleaned with warm, soapy water and a soft cloth. Avoid ultrasonic cleaners, steam cleaners, and harsh chemicals like cosmetics or perfumes, which can damage the stone or cause discoloration. It is best to put on turquoise jewelry after applying makeup and perfume.
- Zircon and Tanzanite: With a moderate hardness of 6.5 to 7, these stones are more durable than turquoise but can still be susceptible to chipping due to their cleavage. They are best cleaned with warm, soapy water and a soft brush. Avoid sudden temperature changes and hard knocks.
- Blue Topaz: As the hardest and most durable of the December stones, blue topaz can withstand more wear. It can be safely cleaned with warm, soapy water and is generally safe from everyday bumps and scratches. However, it is important to avoid prolonged exposure to strong sunlight or high heat, as this can potentially cause its treated color to fade over time.
Conclusion
The birthstones of December offer a remarkable variety of choices, united by a shared palette of beautiful blue hues. From the ancient, protective Turquoise to the brilliantly sparkling Zircon, the rare and transformative Tanzanite, and the durable and affordable Blue Topaz, each gem possesses a distinct character. Their value lies not only in their physical beauty but also in their rich histories, unique geological origins, and the deep symbolic meanings they have held for centuries. For the December-born, these stones provide a personal connection to the natural world, offering a gem for every preference and a legacy of lore and science to be cherished.