December, the final month of the calendar year, is celebrated not only for its festive traditions but also for its association with a trio of captivating gemstones—turquoise, tanzanite, and zircon—each with its own unique history, symbolism, and geological properties. These gemstones, which have been designated as birthstones for December, offer a stunning array of colors and meanings that have captivated cultures for centuries. From ancient civilizations to modern jewelry design, these stones continue to hold a place of significance in both historical and contemporary contexts.
This article will explore the historical and cultural significance of these December birthstones, their geological properties, their symbolism across different cultures, and practical care tips for maintaining their beauty. The discussion is grounded in the detailed information provided by authoritative sources on gemology and historical practices, ensuring a comprehensive and accurate overview.
History and Lore
The concept of birthstones is ancient, with roots in biblical and medieval traditions that assigned specific gemstones to each month of the year. While the earliest references to December birthstones varied, the modern list has evolved significantly over time, incorporating both traditional and newly discovered gems.
According to historical records, the earliest known December birthstone was ruby, mentioned in biblical texts. However, this designation changed over the centuries. By 1870, turquoise had become the primary December birthstone, a designation influenced by the "Gregorian Birthstone Poems" pamphlet by Tiffany & Co. In 1912, the National Association of Jewellers (now known as the Jewellers of America) recognized lapis lazuli as an alternative to turquoise. In 1952, zircon was added to the list by the Jewelry Industry Council of America, and in 2002, tanzanite was included, reflecting the discovery of a new and highly unique gemstone.
The addition of multiple birthstones to December is a strategic choice aimed at offering a variety of options in terms of color, price, and personal meaning. This diversity allows individuals to select a gemstone that best resonates with their preferences and budget, whether they are drawn to the deep blue of lapis lazuli, the vibrant turquoise hues, or the striking violet tones of tanzanite.
The December birthstones also carry rich historical and cultural significance. Turquoise, for instance, has been treasured for thousands of years by ancient civilizations such as the Egyptians, who used it in elaborate jewelry and even in the burial mask of King Tutankhamun. In Native American cultures, particularly in the Southwest, turquoise is considered a sacred stone, often used in ceremonial jewelry and believed to bring protection, healing, and good fortune.
Zircon, though less well-known than turquoise, has a long and fascinating history. It is one of the oldest minerals on Earth, with some zircon crystals dating back over 4.4 billion years. This gemstone has been admired for its brilliant fire and color range, making it a valuable addition to the December birthstone list. Zircon has also been used in jewelry for centuries, particularly in the form of blue zircon, which is prized for its clarity and vibrant color.
Tanzanite, the youngest of the December birthstones, was only discovered in the early 1960s in Tanzania, near Mount Kilimanjaro. This gemstone is unique because it is found only in that region, making it a rare and valuable treasure. Tanzanite’s deep blue to violet hues have made it a favorite in modern jewelry design, and it is often associated with transformation and spiritual growth.
Geological Formation and Sources
Each of the December birthstones is formed through unique geological processes, contributing to their distinct properties and allure.
Turquoise is a phosphate mineral composed of copper, aluminum, and phosphorus. It forms in arid environments where rainwater or melted snow percolates through copper ore deposits, creating an acidic solution that reacts with aluminum and potassium in surrounding rocks. This chemical process results in the formation of turquoise in cavities within weathered volcanic and sedimentary rocks. Major sources of turquoise include the United States (particularly New Mexico and Nevada), Nigeria, China, and Iran.
Zircon is a zirconium silicate that occurs in a wide range of colors, including blue, red, yellow, and green. The blue zircon most commonly associated with December is created through heat treatment, which enhances its natural color and clarity. Zircon is found in many parts of the world, including Australia, Cambodia, India, and Brazil. Its remarkable durability and brilliance make it a popular choice for jewelry.
Tanzanite, as its name suggests, is exclusively found in Tanzania, near Mount Kilimanjaro. It is a trigonal crystal that exhibits trichroism, meaning it can display three different colors—blue, violet, and brown—depending on the angle of light. Tanzanite is formed under high-pressure and high-temperature conditions, and its rarity and beauty have made it a highly sought-after gemstone in the jewelry industry.
Gemological Properties
The December birthstones vary significantly in terms of hardness, clarity, and color, making them suitable for different types of jewelry and purposes.
| Gemstone | Chemical Formula | Hardness (Mohs Scale) | Color | Origin |
|---|---|---|---|---|
| Turquoise | CuAl₆(PO₄)₄(OH)₈·4H₂O | 5–6 | Blue-green | United States, Nigeria, China, Iran |
| Zircon | ZrSiO₄ | 6.5–7.5 | Blue, red, yellow, green | Australia, Cambodia, India, Brazil |
| Tanzanite | Ca₂Al₃(SiO₄)₃(OH) | 6–7 | Blue to violet | Tanzania |
Turquoise is a relatively soft gemstone, with a Mohs hardness of 5–6, making it more susceptible to scratches and damage compared to harder gemstones. It is also porous and can easily absorb oils, pigments, and moisture, which can alter its color. Due to its softness and porosity, turquoise is often treated with stabilizers such as resin or oil to enhance its durability and appearance.
Zircon, on the other hand, is much harder, with a Mohs hardness of 6.5–7.5, depending on the variety. It is known for its brilliance and fire, which rival those of diamonds. Blue zircon, in particular, is highly valued for its vibrant color and clarity, making it a popular choice for rings, pendants, and other fine jewelry. Zircon’s refractive index is also high, contributing to its sparkling appearance.
Tanzanite has a Mohs hardness of 6–7, which makes it relatively durable but still susceptible to scratches and fractures if not handled properly. It is also trichroic, meaning it can display different colors depending on the angle of light. Tanzanite is often heat-treated to enhance its color, and it is prized for its deep blue to violet hues, which are unique to this gemstone.
Symbolism and Metaphysical Beliefs
In addition to their physical properties, the December birthstones are rich in symbolism and metaphysical significance. These meanings have been passed down through generations and are deeply rooted in various cultural traditions.
Turquoise has long been associated with protection, healing, and good fortune. In Egyptian culture, it was believed to ward off evil spirits and bring health to the wearer. In Native American traditions, particularly among the Navajo and Hopi tribes, turquoise is considered a sacred stone that connects the sky and earth, symbolizing fertility, abundance, and spiritual wisdom. It is also believed to promote calmness, emotional balance, and mental clarity.
Zircon is often associated with wisdom, truth, and enlightenment. In ancient times, zircon was believed to have divine powers, and it was used in ceremonial jewelry to enhance intellectual abilities and spiritual insight. In modern metaphysical practices, zircon is said to promote inner peace, emotional stability, and a sense of purpose. It is also believed to enhance clarity of thought and decision-making, making it a valuable stone for those seeking guidance.
Tanzanite is associated with transformation, emotional healing, and spiritual growth. Due to its rarity and the fact that it is found only in Tanzania, it is often seen as a symbol of individuality and uniqueness. In spiritual practices, tanzanite is believed to help individuals release negative emotions, embrace change, and connect with their higher self. It is also associated with love, compassion, and understanding, making it a meaningful gemstone for those going through personal or emotional transformations.
Care and Cleaning
Given their varying hardness and porosity, the December birthstones require different care and cleaning methods to maintain their beauty and longevity.
Turquoise is particularly delicate and requires gentle handling. It should be stored separately from harder gemstones to avoid scratches. It is also important to avoid exposure to harsh chemicals, excessive heat, and prolonged sunlight, as these can cause fading, discoloration, and dehydration. When cleaning turquoise, it is best to use a soft cloth and mild soap and water. Avoid using ultrasonic cleaners or steam cleaners, as these can damage the stone.
Zircon is more durable than turquoise and can be cleaned with standard jewelry cleaning methods. A soft cloth and mild soap and water are sufficient for most zircon jewelry. For more thorough cleaning, ultrasonic cleaners can be used, but it is important to check if the zircon has any inclusions or fractures that may be damaged by the cleaning process. Zircon should also be stored in a dry, cool place to prevent any potential damage.
Tanzanite requires careful handling due to its trichroism and susceptibility to scratches and fractures. It should be stored separately from other gemstones to prevent damage. Tanzanite should also be avoided when exposed to harsh chemicals, heat, and abrasive cleaners. A soft cloth and mild soap and water are the best options for cleaning tanzanite. It is important to avoid using steam cleaners or ultrasonic cleaners, as these can cause internal fractures or color changes.
Conclusion
The December birthstones—turquoise, tanzanite, and zircon—are more than just beautiful gemstones; they are symbols of history, culture, and personal meaning. Each stone has a rich legacy, from the ancient civilizations that revered turquoise for its protective and healing properties, to the discovery of tanzanite in Tanzania, which added a new dimension to the December birthstone list. These gemstones continue to inspire jewelry designers and gemstone enthusiasts with their unique colors, symbolic significance, and geological rarity.
Whether chosen for their historical significance, aesthetic appeal, or metaphysical properties, the December birthstones offer a versatile and meaningful selection for those born in this month. Their diverse characteristics allow individuals to choose a gemstone that best reflects their personality, style, and preferences.
By understanding the history, properties, and care requirements of these gemstones, wearers can appreciate their beauty and significance while ensuring their longevity and durability. The December birthstones are a testament to the enduring connection between gemstones and human culture, serving as a bridge between the past and the present.