December, the final month of the year, is symbolically rich with the themes of reflection, celebration, and transition. In the world of gemstones, December holds a unique position as it is the only month associated with multiple birthstones. These include turquoise, zircon, tanzanite, and blue topaz—each with its own distinct history, properties, and symbolism.
This article explores these gemstones in depth, drawing from historical records, geological data, and cultural lore. We will examine how these stones became associated with December, their physical and metaphysical properties, and their role in jewelry and personal adornment. Whether you are a gemstone enthusiast, a jewelry buyer, or simply curious about the gemstone traditions of the world, this article offers a comprehensive and authoritative look at the December birthstones.
The History and Evolution of December Birthstones
The concept of birthstones is rooted in ancient traditions that linked gemstones to specific months of the year. The earliest known reference to birthstones appears in the High Priest’s Breastplate of Aaron, as described in the Old Testament, which lists twelve gemstones believed to represent the twelve tribes of Israel. These early stones did not map directly to the modern calendar, but they laid the foundation for the symbolic association of gemstones with time and human experience.
Over the centuries, as different cultures and religious traditions developed their own interpretations of gemstone symbolism, the list of birthstones evolved. In the 19th and 20th centuries, the modern list of birthstones was formalized by jewelers’ associations and gemological institutions, leading to the inclusion of multiple stones for some months—including December.
Historical Changes in December's Birthstones
The modern list of December birthstones has undergone several revisions:
- 1870: The Tiffany & Co. "Gregorian Birthstone Poems" pamphlet listed turquoise as the December birthstone.
- 1912: The National Association of Jewellers (now the American Gem Society) designated turquoise as the primary December birthstone and included lapis lazuli as an alternative.
- 1952: Zircon was added to the December birthstone list by the Jewelry Industry Council of America.
- 2002: Tanzanite was added to the U.S. birthstone list by the American Gem Society.
This evolution reflects not only the shifting trends in the jewelry industry but also the introduction of newly discovered gemstones and the growing appreciation for a broader range of gem materials.
Geological Formation and Sources
Each of December’s birthstones has a distinct geological origin and formation process. Understanding these processes helps to appreciate the rarity, beauty, and value of each gemstone.
Turquoise
Turquoise is a hydrated phosphate of aluminum and copper, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in arid environments where copper-rich minerals react with water and phosphorus. This typically occurs in the weathering zones of copper deposits, often in association with volcanic rock or sedimentary formations.
Turquoise is known for its porous structure, which makes it susceptible to staining and color change. It has a Mohs hardness of 5 to 6, meaning it is relatively soft and can be easily scratched or damaged. This softness also makes it prone to discoloration when exposed to oils, pigments, and moisture.
Natural sources of turquoise include Iran, Nevada (USA), China, Mexico, and Australia. The finest turquoise is often found in Nevada, where it is prized for its deep blue color and minimal matrix (the dark mineral veins that form during its formation).
Zircon
Zircon is a zirconium silicate with the chemical formula ZrSiO₄. It is a high refractive index gemstone, which gives it a brilliant, diamond-like sparkle. Zircon forms in igneous and metamorphic rocks and is often found in beach sands and alluvial deposits.
Zircon is known for its wide range of colors, including blue, brown, red, green, and colorless. The blue zircon variant, which is the most commonly associated with December, is created through heat treatment, as natural blue zircon is rare.
Blue zircon is primarily sourced from Sri Lanka, Zambia, and Brazil. It has a Mohs hardness of 6 to 7.5, making it more durable than turquoise but still somewhat fragile compared to other gemstones.
Tanzanite
Tanzanite is a trigonal mineral with the chemical formula Ca₂Al₃(BO₃)Si₃O₁₀(OH)₂. It is a trichroic gemstone, meaning it can display three different colors under different lighting conditions. The most common and desirable color is a deep blue to violet hue.
Tanzanite is unique in that it is found only in one location in the world: the Merelani Hills of Tanzania, near the city of Arusha. This limited geographic source contributes to its rarity and value.
Tanzanite has a Mohs hardness of 6 to 7, and it requires careful handling due to its cleavage planes. It is typically heat-treated to enhance its color, a process that is now standard in the gemstone industry.
Tanzanite was discovered in 1967, making it one of the newest gemstones to be recognized. It was officially added to the U.S. birthstone list in 2002.
Blue Topaz
Blue topaz is a silicate mineral with the chemical formula Al₂SiO₄(F,OH)₂. It is a hexagonal crystal system gemstone, known for its brilliant clarity and light refractive qualities.
Blue topaz is created through irradiation and heat treatment, as natural blue topaz is extremely rare. The most popular blue color is sky blue or London blue, and the gemstone is highly valued for its durability and affordability.
Blue topaz is primarily sourced from Brazil, Nigeria, and the United States. It has a Mohs hardness of 8, making it one of the most durable of the December birthstones.
Symbolism and Metaphysical Beliefs
Throughout history, gemstones have been attributed with spiritual, emotional, and physical properties. These beliefs often vary across cultures but reflect a shared human fascination with the power of gemstones.
Turquoise
Turquoise has long been regarded as a stone of protection and wisdom. Ancient Egyptian pharaohs, Persian emperors, and Chinese emperors all valued turquoise for its spiritual and symbolic significance. In Native American traditions, turquoise is associated with healing, luck, and spiritual connection.
It is also believed to enhance communication, calm the mind, and promote emotional stability. Some traditions suggest that turquoise can protect against harm, particularly during travel or in times of uncertainty.
Zircon
Zircon is often described as a stone of transformation and inner wisdom. It is believed to enhance spiritual perception, balance the chakras, and stimulate intuition. Zircon is also associated with joy, emotional healing, and mental clarity.
In ancient times, zircon was used in meditative practices and was believed to connect the wearer to higher states of consciousness. It is considered a stone of the heart and mind, promoting emotional balance and inner strength.
Tanzanite
Tanzanite is known for its healing and transformative properties. It is often associated with emotional healing, spiritual awakening, and self-discovery. Tanzanite is believed to activate the throat, third eye, and crown chakras, which are linked to communication, intuition, and spiritual connection.
It is also thought to enhance psychic abilities, promote emotional stability, and encourage a deeper understanding of oneself and others. Tanzanite is particularly valued for its soothing energy, making it a popular choice for those seeking inner peace and emotional balance.
Blue Topaz
Blue topaz is often described as a stone of calming energy and emotional strength. It is believed to enhance mental clarity, reduce stress, and promote a sense of inner peace. Blue topaz is also associated with self-esteem, learning, and spiritual growth.
It is considered a stone of wisdom and communication, helping the wearer to think clearly and express themselves confidently. In Hindu tradition, blue topaz is believed to align the body’s energy meridians, promoting overall well-being and emotional harmony.
Care and Maintenance of December Birthstones
Each of the December birthstones requires specific care due to its physical properties. Proper care ensures that the gemstone retains its beauty and durability over time.
Turquoise
- Cleaning: Turquoise should be cleaned gently with a soft, damp cloth. Avoid using harsh chemicals, ultrasonic cleaners, or steam cleaners, as these can damage the stone.
- Storage: Store turquoise separately from other gemstones to avoid scratching. Keep it in a cool, dry place to prevent drying out and color loss.
- Avoiding Exposure: Turquoise is sensitive to oils, cosmetics, and moisture, so it is best to remove turquoise jewelry before applying makeup or perfume.
Zircon
- Cleaning: Clean zircon with warm, soapy water and a soft cloth. Avoid harsh chemicals or ultrasonic cleaners, as zircon can be damaged by excessive heat or vibration.
- Storage: Store zircon in a soft pouch or separate compartment to avoid scratching.
- Avoiding Exposure: Zircon is not resistant to cleavage, so it should be handled carefully to avoid cracking or chipping.
Tanzanite
- Cleaning: Tanzanite should be cleaned gently with warm, soapy water and a soft cloth. Avoid harsh chemicals, ultrasonic cleaners, and steam cleaners, as these can damage the stone.
- Storage: Store tanzanite separately from other gemstones to prevent scratching. It should be kept in a cool, dry place.
- Avoiding Exposure: Tanzanite has cleavage, so it should be handled carefully to avoid cracking or chipping. Avoid exposing it to extreme temperatures or direct sunlight for prolonged periods.
Blue Topaz
- Cleaning: Blue topaz can be cleaned with warm, soapy water and a soft cloth. It can also be cleaned with an ultrasonic cleaner.
- Storage: Store blue topaz separately from other gemstones to prevent scratching.
- Avoiding Exposure: Blue topaz is relatively durable, but it should still be handled with care to avoid scratching or chipping.
Conclusion
December’s birthstones—turquoise, zircon, tanzanite, and blue topaz—represent a unique and diverse array of gemstones, each with its own rich history, distinct properties, and symbolic meaning. From the ancient use of turquoise in royal courts to the modern discovery of tanzanite in the Merelani Hills, these gemstones reflect the evolving relationship between humanity and the natural world.
Whether you are drawn to the spiritual properties of turquoise, the transformative energy of zircon, the soothing aura of tanzanite, or the calming clarity of blue topaz, there is a December birthstone for every personality and style. These gemstones not only serve as beautiful adornments but also carry the legacy of centuries, connecting us to the past while illuminating the present.
As you explore the world of December birthstones, you are not only discovering gemstones—you are uncovering the stories, traditions, and values that have shaped human culture for millennia.