December, the final month of the year, is distinguished in the world of gemology by its association with a rich and varied selection of birthstones. Unlike most months that are linked to a single gemstone, December is notable for having multiple birthstones — a unique trait that reflects both its historical significance and the diversity of gemstone options available to consumers and collectors alike. The December birthstones include Turquoise, Tanzanite, Zircon, and Blue Topaz. Each of these stones possesses a distinct hue of blue, ranging from the deep, violet tones of Tanzanite to the vibrant sky blues of Turquoise and Blue Topaz. This month is also associated with the zodiac signs Sagittarius and Capricorn, and as such, its gemstones carry symbolic meanings that align with these signs, including protection, truth, and calmness.
This article delves into the gemological properties, historical significance, cultural lore, and practical considerations for caring for these December birthstones. It explores how these stones were historically valued, the geological processes that formed them, and their current roles in jewelry and spiritual practices. In addition, the article provides guidance on the best ways to care for these stones, ensuring they remain beautiful and durable for generations to come.
History and Lore
The history of December’s birthstones is deeply rooted in cultural traditions, ancient beliefs, and evolving jewelry trends. Among these, Turquoise stands out as one of the oldest and most historically significant. This semi-translucent to opaque gemstone has been cherished for millennia. Ancient Egyptian pharaohs and rulers adorned themselves with turquoise, recognizing its beauty and the protective powers it was believed to bestow. Chinese artisans, as early as 3,000 years ago, carved turquoise into intricate designs, further cementing its cultural importance in the East. In the West, the name "turquoise" derives from the French phrase pierre turquoise, meaning "Turkish stone," a reference to the stone’s initial introduction to Europe through Turkish bazaars.
Turquoise was not only valued for its aesthetic appeal but also for its perceived spiritual and protective properties. In medieval Europe, it was believed that turquoise could protect the wearer from falling, especially off horses, and would break into pieces in the event of an impending disaster. Hindu mystics also held turquoise in high regard, believing that seeing it after the new moon ensured great wealth. Native American cultures, particularly the Apache, associated turquoise with the end of the rainbow and saw it as a symbol of good fortune and spiritual guidance.
The other December birthstones, though more modern in their official recognition, also have rich historical and cultural backgrounds. Tanzanite, discovered in 1967 in Tanzania, was added to the December birthstone list in 2002. Its rarity and deep violet-blue color have made it a popular choice in modern jewelry, especially for those seeking a unique and valuable gemstone. Zircon, a traditional December birthstone, has been known for centuries and is often associated with clarity and wisdom. It has been historically used in jewelry and was later included in the modern December birthstone list by the GIA in 1952. Blue Topaz, while not traditionally considered a December birthstone, was added to the list in modern times due to its durability and affordability, making it a practical option for everyday jewelry.
The inclusion of multiple birthstones for December reflects a combination of historical significance, gemological diversity, and commercial appeal. The practice of assigning birthstones to months dates back to ancient times, with various cultures attributing different stones to different periods of the year. In 1912, the National Association of Jewelers in the United States standardized the unofficial American birthstones, and the list has since been updated to include new discoveries like Tanzanite. These updates ensure that December's birthstone selection remains relevant and appealing to contemporary tastes.
Geological Formation and Sources
The geological processes that formed the December birthstones are as fascinating as the stones themselves. Each of these gemstones has a unique formation history and is found in distinct geographical locations around the world.
Turquoise is formed by the interaction of groundwater containing copper with the bedrock. Over time, the copper reacts with other minerals, creating an opaque stone with striking shades of blue and green. The distinct matrix patterns—dark lines and shapes that appear in many turquoise stones—are remnants of the surrounding rock. Historically, the finest turquoise was mined in Iran, a region known for producing high-quality stones. Today, major sources include the United States (particularly the Southwest), Tibet, and India. The presence of copper in the formation process is essential, as it gives turquoise its characteristic blue color.
Tanzanite, in contrast, is a relatively recent discovery. It was first found in 1967 in the Merelani Hills of Tanzania, a location unique to this gemstone. Tanzanite is a type of zoisite that exhibits trichroism, meaning it can appear in three different colors—blue, violet, and brown—depending on the angle of light. This phenomenon is due to the crystal structure of the stone. The rarity of tanzanite, combined with its deep, rich color, makes it one of the most valuable December birthstones.
Zircon, a traditional December birthstone, has been known for centuries and is found in various parts of the world. It is a zirconium silicate that forms in igneous rocks and is often found in metamorphic and sedimentary rocks as well. Zircon is particularly notable for its high refractive index and strong dispersion, which gives it a brilliant, fire-like appearance. It is found in countries such as Cambodia, Sri Lanka, and parts of Africa and Australia. The blue variety of zircon, known as "star blue zircon," is especially prized for its vibrant color and clarity.
Blue Topaz, while not traditionally considered a December birthstone, has gained popularity in modern times. It is a type of topaz that has been heat-treated to enhance its blue color. Natural blue topaz is rare, and most of the blue topaz available in the market has been treated to achieve its coloration. The stone is primarily found in countries such as Brazil, Mexico, Nigeria, and the United States. Blue topaz is known for its durability, with a hardness of 8 on the Mohs scale, making it suitable for everyday wear.
Gemological Properties
Understanding the gemological properties of December’s birthstones is essential for both collectors and jewelers. These properties include hardness, color, refractive index, and other characteristics that determine a stone’s suitability for jewelry and its overall value.
Turquoise has a hardness of 5 to 6 on the Mohs scale, making it relatively soft compared to other gemstones. This lower hardness means that turquoise is more susceptible to scratches and abrasions. It is also porous and can absorb oils and other substances, which can affect its color and appearance over time. The refractive index of turquoise ranges from 1.61 to 1.65, and it is typically opaque or semi-translucent, with a waxy luster. The presence of matrix patterns and the stone’s color variations contribute to its unique beauty and make each turquoise gemstone one of a kind.
Tanzanite is a harder gemstone, with a hardness of 6 to 7 on the Mohs scale. It has a refractive index of 1.69 to 1.70 and exhibits strong pleochroism, meaning it can appear in different colors when viewed from different angles. Tanzanite is typically cut in such a way that the blue color is emphasized, as this is the most desirable hue. Its deep violet-blue color is due to the presence of vanadium, and it is often treated to enhance its color and clarity. Tanzanite’s rarity and beauty make it one of the most valuable December birthstones.
Zircon is known for its high refractive index and strong dispersion, which gives it a brilliant, fire-like appearance. It has a hardness of 7.5 to 8 on the Mohs scale, making it more durable than turquoise but slightly less hard than topaz. Zircon is available in a range of colors, including blue, yellow, green, and red. The blue variety, often referred to as "star blue zircon," is particularly popular as a December birthstone due to its vibrant color and brilliance. Zircon is also known for its high luster and is often cut in a variety of styles to showcase its fire and color.
Blue Topaz is one of the hardest December birthstones, with a hardness of 8 on the Mohs scale. This makes it ideal for everyday wear, as it is less likely to scratch or chip. Blue topaz has a refractive index of 1.62 to 1.64 and is typically colorless in its natural state. The blue coloration is achieved through heat treatment, which enhances the stone’s natural properties. Blue topaz is known for its clarity and brilliance, making it a popular choice for jewelry. It is also relatively affordable compared to other December birthstones, making it an accessible option for many consumers.
Symbolism and Metaphysical Beliefs
December’s birthstones have long been associated with various symbolic meanings and metaphysical properties, reflecting the beliefs and traditions of different cultures. These stones are often worn not only for their aesthetic appeal but also for their perceived spiritual and protective qualities.
Turquoise is perhaps the most spiritually significant of the December birthstones. It has been regarded as a stone of protection, good fortune, and wisdom in many cultures. In ancient Egypt, turquoise was believed to ward off evil and bring prosperity to the wearer. In Native American traditions, it was considered a sacred stone that connected the earthly and spiritual realms. The Apache believed that following a rainbow to its end would lead them to turquoise, which was thought to bring good luck and spiritual guidance. In medieval Europe, turquoise was also believed to protect against falls and disasters, with the belief that the stone would break into pieces if danger was near.
Tanzanite, being a more modern discovery, has not had as long a history of symbolic associations as the other December birthstones. However, it is often associated with transformation, healing, and emotional balance. Its deep violet-blue color is thought to promote calmness and inner peace. In spiritual practices, tanzanite is sometimes used to open the throat and third eye chakras, enhancing communication and intuition. It is also believed to help individuals process emotions and move through periods of change more smoothly.
Zircon has been associated with clarity, wisdom, and balance in various cultures. It is often used in meditation and spiritual practices to enhance mental clarity and emotional stability. Zircon is also believed to protect against negative energies and promote a sense of harmony. In some traditions, it is considered a stone of transformation and is used to help individuals overcome obstacles and achieve their goals. Its brilliance and fire-like appearance have also made it a symbol of passion and energy.
Blue Topaz is associated with calming emotions and enhancing intuition. It is believed to bring a sense of tranquility and peace to the wearer, helping to reduce stress and anxiety. Blue topaz is also thought to enhance communication and self-expression, making it a popular choice for those who seek to improve their interpersonal relationships. In some spiritual traditions, blue topaz is used to support healing and to promote a sense of inner balance and harmony.
Care and Cleaning
Proper care and cleaning are essential for maintaining the beauty and durability of December’s birthstones. Each stone has unique properties that require specific handling and cleaning methods.
Turquoise is relatively soft and porous, making it susceptible to damage from harsh chemicals, heat, and abrasives. To clean turquoise, it is recommended to use a soft cloth and a mild soap solution. Avoid using ultrasonic or steam cleaners, as these can cause the stone to crack or lose its color. It is also important to store turquoise away from direct sunlight and heat sources to prevent fading. Due to its porosity, turquoise can absorb oils and lotions, which can dull its appearance over time. Therefore, it is best to remove turquoise jewelry before applying cosmetics or perfumes.
Tanzanite is more durable than turquoise but still requires gentle handling. It can be cleaned with a soft cloth and a mild soap solution. Avoid using harsh chemicals or abrasive cleaners, as these can scratch the surface of the stone. Tanzanite is also sensitive to heat and should not be exposed to high temperatures for extended periods. When storing tanzanite, it is best to keep it in a cool, dry place to prevent any changes in color or clarity.
Zircon is a relatively hard gemstone, with a hardness of 7.5 to 8 on the Mohs scale. This makes it suitable for everyday wear and less prone to scratches. Zircon can be cleaned with a soft cloth and a mild soap solution. Avoid using ultrasonic cleaners, as these can sometimes cause damage to the stone, especially if it has been treated to enhance its color. Zircon should also be stored in a cool, dry place to prevent any changes in its appearance.
Blue Topaz is one of the most durable December birthstones, with a hardness of 8 on the Mohs scale. This makes it ideal for everyday wear and less susceptible to scratches and abrasions. Blue topaz can be cleaned with a soft cloth and a mild soap solution. It is also safe to use ultrasonic and steam cleaners for blue topaz. However, it is important to avoid exposing blue topaz to high temperatures, as this can cause the color to fade. When storing blue topaz, it is best to keep it in a cool, dry place to preserve its brilliance and clarity.
Conclusion
December’s birthstones offer a rich and diverse selection of gemstones, each with its own unique properties, historical significance, and cultural associations. From the ancient traditions surrounding turquoise to the modern discovery of tanzanite, these stones have played important roles in jewelry, spirituality, and personal adornment. Their varied hues of blue reflect the winter season and provide a range of options for those seeking a meaningful and beautiful gemstone. Whether valued for their protective qualities, symbolic meanings, or aesthetic appeal, December’s birthstones continue to captivate and inspire. Understanding their gemological properties, geological origins, and care requirements ensures that these stones can be enjoyed and preserved for generations to come.