December is unique among all months in the world of birthstones, as it is the only month recognized for having four official birthstones: Turquoise, Tanzanite, Blue Topaz, and Zircon. These gemstones are all associated with the cool tones of winter and have each developed their own rich histories and gemological identities. While the tradition of assigning gemstones to specific months dates back to ancient times, the December birthstones have undergone significant evolution in their recognition and popularity. This article explores the origins, gemological properties, cultural symbolism, and practical considerations for each of these four December birthstones, drawing on the most authoritative and well-corroborated information available from historical, geological, and commercial sources.
History and Lore
The association of gemstones with specific months is an ancient tradition that originated in Mesopotamia and was later adopted by the Greeks and Romans. These early cultures believed that each gemstone was linked to a particular month and had protective or healing properties that were most effective during that time. Over time, these associations evolved, and by the 20th century, the list of birthstones had been formalized in the United States by the National Association of Jewelers in 1912.
Initially, December was associated only with Turquoise and Lapis Lazuli, both of which were highly valued for their protective and spiritual properties. However, as new gemstones were discovered and commercialized, the list expanded. Zircon was added in 1952 as a more durable alternative to Lapis Lazuli, and Blue Topaz was officially recognized in 1998. Finally, Tanzanite, a gemstone discovered in 1967, was added in 2002, marking the most recent addition to the December birthstone list.
The expansion of the list reflects both the evolving nature of gemstone appreciation and the practical considerations of the jewelry industry. Blue Topaz, for example, is more durable and affordable than some of the other December birthstones, making it a popular choice for everyday jewelry. Tanzanite, on the other hand, is valued for its rarity and striking color, even though it is softer and requires more careful handling.
Geological Formation and Sources
Each of the four December birthstones has a unique geological origin and is found in distinct locations around the world. Understanding the geological processes that form these gemstones provides insight into their rarity, coloration, and physical properties.
Turquoise
Turquoise is a hydrated phosphate of aluminum and copper. It typically forms in arid regions where copper-rich rocks are exposed to the surface and subjected to weathering and chemical alteration. This process creates the distinctive blue to green hues for which turquoise is known. The most well-known sources of turquoise include Nevada, Arizona, and New Mexico in the United States, as well as Iran, China, and Egypt.
Turquoise has been used for millennia in jewelry and ceremonial objects, particularly in ancient Egypt and the American Southwest. The stone is often opaque and may contain veins or patterns known as "matrix," which can vary in color depending on the minerals present in the surrounding rock.
Tanzanite
Tanzanite is a variety of the mineral columbite, and its vibrant blue to violet-blue color is due to trace amounts of vanadium within the crystal structure. It was discovered in 1967 in Tanzania, near the base of Mount Kilimanjaro, which is the only place in the world where tanzanite is found. This geographical exclusivity makes tanzanite one of the rarest gemstones in the world.
Tanzanite is trichroic, meaning it can display three different colors when viewed from different angles—blue, violet, and brown. This property makes it a unique and visually intriguing gemstone. Due to its rarity and the limited mining area, tanzanite is often considered a collector’s gemstone and is highly valued in the jewelry market.
Blue Topaz
Topaz is a silicate mineral with the chemical formula Al₂SiO₄(F,OH)₂. In its natural form, topaz is usually colorless, but it can occur in a range of colors, including yellow, orange, and blue. Natural blue topaz is extremely rare, so most of the blue topaz found in jewelry is the result of irradiation and heat treatment. These treatments alter the crystal structure of the stone, producing the deep blue or sky-blue hues that are so desirable in jewelry.
Blue topaz is mined in several locations around the world, including Sri Lanka, Brazil, Mexico, Nigeria, and the United States. It was officially recognized as a December birthstone in 1998, and its inclusion reflects the growing demand for durable and versatile gemstones in the jewelry industry.
Zircon
Zircon is a zirconium silicate with the chemical formula ZrSiO₄. It is one of the oldest known gemstones and has been used in jewelry and decorative objects for thousands of years. Zircon can occur in a wide range of colors, including blue, red, yellow, and green, but the blue variety is the most commonly recognized as a December birthstone.
Blue zircon is created through heat treatment, which stabilizes the color and enhances its brilliance. It is found in various parts of the world, including Australia, Cambodia, and Thailand. Zircon was officially added to the December birthstone list in 1952, replacing lapis lazuli as a more durable and commercially viable option.
Gemological Properties
Each of the four December birthstones has distinct gemological properties that affect their use in jewelry, their durability, and their value. These properties include hardness on the Mohs scale, color, clarity, cut, and chemical composition.
Turquoise
Turquoise has a Mohs hardness of 5 to 6, which means it is relatively soft and prone to scratches and abrasions. It is also porous and sensitive to acids, making it vulnerable to damage from household chemicals, perfumes, and lotions. Because of these properties, turquoise is best suited for necklaces, pendants, and statement pieces, rather than rings or bracelets that are subject to frequent contact and wear.
Turquoise is typically opaque and can contain veins or patterns known as "matrix," which can vary in color and appearance. The most valuable turquoise is deep blue with minimal matrix, as this color is associated with the highest quality and most desirable appearance.
Tanzanite
Tanzanite has a Mohs hardness of 6 to 7, which means it is relatively soft and requires careful handling to avoid scratches and damage. It is also trichroic, meaning it can display three different colors when viewed from different angles—blue, violet, and brown. This property makes it a visually interesting gemstone but also means that the cut and orientation of the stone are crucial for maximizing its color and brilliance.
Tanzanite is also heat-sensitive, and exposure to high temperatures can cause it to lose its color or become discolored. Because of its rarity and the limited mining area, tanzanite is often considered a collector’s gemstone and is highly valued in the jewelry market.
Blue Topaz
Blue topaz has the highest Mohs hardness of the four December birthstones, with a rating of 8. This makes it the most durable and suitable for everyday wear, particularly in rings, earrings, and other jewelry that is subject to frequent use. Its high hardness also makes it resistant to scratches and abrasions, which is an important consideration for jewelry that is worn regularly.
Blue topaz is available in a range of blue hues, from sky blue to deep London blue, and its clarity is typically high. Because of its durability and affordability, blue topaz is a popular choice for engagement rings, pendants, and daily wear jewelry.
Zircon
Zircon has a Mohs hardness of 6.5 to 7.5, which means it is relatively durable and can be worn in everyday jewelry, although it is not as hard as blue topaz. It is also pleochroic, meaning it can display different colors when viewed from different angles, which can affect its appearance depending on the cut and orientation.
Zircon is known for its high refractive index and dispersion, which gives it a brilliant and fiery appearance. This makes it an excellent choice for halo settings, accent stones, and earrings, where its sparkle can be showcased effectively.
Symbolism and Metaphysical Beliefs
Each of the four December birthstones carries its own rich history of symbolism and metaphysical beliefs, which have evolved over time. These beliefs often reflect the cultural and spiritual significance of the stones and continue to influence their popularity in jewelry and personal adornment.
Turquoise
Turquoise has been revered for centuries for its protective and healing properties. In ancient Egypt, it was believed to bring protection and good fortune, and it was often used in amulets and ceremonial objects. In the American Southwest, Native American tribes used turquoise in jewelry and ceremonial items, believing it to have spiritual and healing powers.
Today, turquoise is still associated with protection, healing, and friendship, and it is often worn as a talisman to ward off negative energy and promote positive change. It is also believed to enhance communication and self-expression, making it a popular choice for those who seek clarity and confidence.
Tanzanite
Tanzanite is associated with transformation, intuition, and spiritual growth. Its rare and vibrant color is believed to enhance one’s ability to connect with higher realms and to access deeper levels of consciousness. It is often used in meditation and spiritual practices to promote inner peace and emotional balance.
Due to its rarity and the limited mining area, tanzanite is also seen as a symbol of individuality and exclusivity. It is believed to help one embrace their unique path and to encourage self-acceptance and personal growth.
Blue Topaz
Blue topaz is associated with clarity, communication, and calmness. It is believed to enhance mental clarity and to help one express their thoughts and emotions with greater ease and confidence. It is also thought to promote emotional balance and serenity, making it an excellent choice for those who seek inner peace and stability.
Blue topaz is also associated with good fortune and prosperity, and it is often worn as a talisman to attract positive energy and opportunities. Its high durability and affordability make it a practical and meaningful choice for everyday jewelry.
Zircon
Zircon is associated with wisdom, prosperity, and good fortune. It is believed to enhance one’s ability to think clearly and to make wise decisions. It is also thought to attract wealth and abundance, making it a popular choice for those who seek financial success and stability.
Zircon is also believed to promote inner strength and resilience, helping one to overcome challenges and to maintain a positive outlook. Its brilliant and fiery appearance makes it a powerful and inspiring gemstone, and its association with prosperity and wisdom continues to influence its popularity in jewelry and personal adornment.
Care and Cleaning
Proper care and cleaning are essential for preserving the beauty and longevity of any gemstone, especially for those that are softer or more sensitive to damage. The following guidelines provide practical advice for caring for the four December birthstones based on their physical properties and vulnerabilities.
Turquoise
Turquoise is relatively soft and porous, making it vulnerable to scratches, abrasions, and chemical damage. To care for turquoise jewelry, it should be stored in a soft cloth or jewelry box to prevent scratches and kept away from acids, perfumes, and lotions. It should also be avoided contact with water, as prolonged exposure can cause it to become dull or discolored.
To clean turquoise, a soft, damp cloth can be used to gently wipe away dirt and debris. It should be avoided using ultrasonic cleaners or steam cleaners, as these can damage the stone. If necessary, a mild soap and water solution can be used, but it should be rinsed thoroughly and dried immediately.
Tanzanite
Tanzanite is relatively soft and can be easily scratched or discolored if not handled carefully. To care for tanzanite jewelry, it should be stored in a soft cloth or jewelry box to prevent scratches and kept away from high temperatures and direct sunlight, as these can cause it to lose its color or become discolored.
To clean tanzanite, a soft, damp cloth can be used to gently wipe away dirt and debris. It should be avoided using ultrasonic cleaners or steam cleaners, as these can cause it to become discolored or damaged. If necessary, a mild soap and water solution can be used, but it should be rinsed thoroughly and dried immediately.
Blue Topaz
Blue topaz is the hardest of the four December birthstones, with a Mohs hardness of 8, making it suitable for everyday wear and more resistant to scratches and abrasions. However, it is still important to take care of blue topaz jewelry to ensure its longevity.
To care for blue topaz, it should be stored in a jewelry box or soft cloth to prevent scratches and kept away from harsh chemicals and abrasives. To clean blue topaz, a soft, damp cloth can be used to gently wipe away dirt and debris. It can also be cleaned with a mild soap and water solution, but it should be rinsed thoroughly and dried immediately.
Zircon
Zircon is relatively durable, with a Mohs hardness of 6.5 to 7.5, making it suitable for everyday wear. However, it is still vulnerable to scratches and damage if not handled carefully. To care for zircon jewelry, it should be stored in a jewelry box or soft cloth to prevent scratches and kept away from harsh chemicals and abrasives.
To clean zircon, a soft, damp cloth can be used to gently wipe away dirt and debris. It can also be cleaned with a mild soap and water solution, but it should be rinsed thoroughly and dried immediately. It should be avoided using ultrasonic cleaners or steam cleaners, as these can cause it to become discolored or damaged.
Conclusion
The four December birthstones—Turquoise, Tanzanite, Blue Topaz, and Zircon—each have a rich history, unique gemological properties, and distinct cultural significance. From the ancient protective powers of turquoise to the rare and vibrant beauty of tanzanite, these gemstones offer a diverse range of colors, meanings, and uses in jewelry and personal adornment.
The expansion of the December birthstone list reflects both the evolving nature of gemstone appreciation and the practical considerations of the jewelry industry. Blue Topaz, for example, is a durable and affordable option for everyday wear, while Tanzanite is valued for its rarity and striking color. Understanding the history, properties, and symbolism of these gemstones can help individuals make informed choices when selecting jewelry and can also deepen their appreciation for the rich traditions and cultural significance of birthstones.
Whether worn for their beauty, their meaning, or their rarity, the December birthstones continue to captivate and inspire, offering a unique and meaningful way to celebrate the December birthday and the individual who wears them.