December, the final month of the year, is marked by a rich collection of gemstones that reflect its festive and transformative energy. Known for its chill and celebration, December has historically been associated with a variety of gemstones, each contributing to its unique charm. The month is notable for having three officially recognized birthstones — turquoise, tanzanite, and blue zircon — with blue topaz and lapis lazuli also being traditionally recognized. These stones vary in color, symbolism, and geological properties, offering a diverse selection for jewelry and personal adornment.
The birthstone tradition, which dates back to ancient civilizations, assigns specific gemstones to each month of the year. These gems are believed to carry specific meanings, properties, and even spiritual significance. For December, the birthstones represent a blend of ancient wisdom and modern appreciation, combining historical roots with contemporary trends in jewelry and gemology.
This article delves into the December birthstones, focusing on their history, cultural significance, gemological properties, and care recommendations. By exploring these elements, we aim to provide a comprehensive understanding of the December birthstones for gemstone enthusiasts, jewelry buyers, and students of gemology.
History and Lore
The tradition of birthstones is deeply rooted in historical and religious contexts. The earliest known references to birthstones can be traced back to the Breastplate of Aaron, described in the biblical Book of Exodus (28:15–30). This sacred artifact was adorned with twelve gemstones, each corresponding to one of the twelve tribes of Israel. Over time, these stones were associated with the months of the year and later with specific zodiac signs.
December, as the final month of the year, has seen several changes in its designated birthstone. In the early 19th century, turquoise was designated as the primary December birthstone by the National Association of Jewellers (now the Jewellers of America). Later, in 1912, lapis lazuli was added as an alternative. In 1952, zircon was included, and in 2002, tanzanite was officially recognized as a December birthstone. This evolution reflects the dynamic nature of the birthstone tradition and the influence of market trends and geological discoveries.
Each of the December birthstones carries its own historical and cultural significance. Turquoise, one of the oldest known gemstones, has been used in jewelry and ceremonial objects for thousands of years. It was highly valued by ancient civilizations such as the Egyptians, Aztecs, and Chinese. In many cultures, turquoise symbolizes protection, good fortune, and spiritual connection.
Tanzanite, discovered in Tanzania in 1967, is a relatively modern gemstone. Its vibrant blue to violet color and limited geographic origin have made it a sought-after gem in contemporary jewelry. Zircon, on the other hand, is one of the oldest minerals on Earth, with some specimens estimated to be over 4 billion years old. It is prized for its brilliance and variety of colors, particularly in its blue form.
Geological Formation and Sources
The geological formation and sources of the December birthstones highlight the natural processes that create these unique gemstones.
Turquoise
Turquoise is a phosphate mineral composed of copper and aluminum, with a chemical formula of CuAl₆(PO₄)₄(OH)₈·4H₂O. It forms in the oxidation zones of copper deposits, typically in arid regions where water can leach copper from the surrounding rock. This process results in the formation of turquoise nodules and veins.
Major sources of turquoise include the United States (particularly Nevada and Arizona), Iran, China, and Egypt. The most highly prized turquoise is often found in the United States, where it has been mined for centuries. The color of turquoise can vary from deep blue to greenish-blue, depending on the presence of other minerals and impurities.
Tanzanite
Tanzanite is a rare and valuable gemstone, a type of zoisite mineral that was discovered in Tanzania in 1967 near Mount Kilimanjaro. The mineral was originally brown but was later heat-treated to reveal its striking blue to violet hues. Tanzanite is known for its strong pleochroism, meaning it displays different colors when viewed from different angles.
Tanzanite is found only in the Merelani Hills of Tanzania, making it one of the most exclusive gemstones in the world. Its limited availability and unique coloration contribute to its high value in the jewelry market.
Blue Zircon
Zircon is a zirconium silicate mineral with the chemical formula ZrSiO₄. It is found in a variety of colors, but the blue form is the most commonly associated with the December birthstone. Blue zircon is created through heat treatment, which alters the mineral’s structure and produces a vibrant blue color.
Zircon is found in various parts of the world, including Australia, Thailand, Cambodia, and Brazil. The gemstone is known for its high refractive index, which gives it a brilliant sparkle and a "fire" similar to that of diamond. Blue zircon is particularly popular in jewelry due to its affordability and beauty.
Gemological Properties
Understanding the gemological properties of the December birthstones is essential for appreciating their beauty and durability.
Turquoise
Turquoise has a hardness of 5 to 6 on the Mohs scale, which makes it relatively soft and susceptible to scratches and abrasions. Its specific gravity ranges from 2.6 to 2.8, and it has a waxy to greasy luster. Turquoise is often stabilized with resins to enhance its durability and color.
Turquoise is porous and can be easily damaged by heat, chemicals, and excessive moisture. It is typically cut into cabochons to showcase its color and pattern, rather than being faceted. The gemstone is also known for its chatoyancy, a cat’s-eye effect that can appear in some specimens.
Tanzanite
Tanzanite has a hardness of 6 to 7 on the Mohs scale, making it more durable than turquoise but still relatively soft compared to other gemstones. It has a refractive index of 1.694 to 1.700 and exhibits strong pleochroism, displaying different colors when viewed from different angles.
Tanzanite is sensitive to high temperatures and can be damaged by sudden temperature changes. It is also susceptible to chemical damage from acids and other harsh substances. Tanzanite is typically cut into faceted gemstones to enhance its brilliance and color.
Blue Zircon
Blue zircon has a hardness of 7.5 to 8 on the Mohs scale, making it a relatively durable gemstone. It has a refractive index of 1.92 to 2.00, which contributes to its brilliance and "fire." Blue zircon is known for its high dispersion, which creates a rainbow-like effect when light passes through it.
Zircon is also known for its high specific gravity, which gives it a heavy, substantial feel. It is often cut into brilliant or modified brilliant cuts to maximize its fire and sparkle. Blue zircon is a popular alternative to diamond due to its affordability and beauty.
Symbolism and Metaphysical Beliefs
The December birthstones carry a rich tapestry of symbolism and metaphysical beliefs across different cultures and eras.
Turquoise
Turquoise has long been associated with protection, healing, and spiritual connection. In ancient Egypt, it was used in amulets and burial jewelry to ward off evil and ensure safe passage into the afterlife. In the Americas, Native American tribes such as the Navajo and Zuni used turquoise in their jewelry and ceremonies, believing it to be a sacred stone that brought balance and harmony.
Turquoise is also associated with wisdom, truth, and communication. It is believed to enhance intuition and promote open and honest communication. In some cultures, turquoise is considered a stone of transformation, helping individuals navigate change and uncertainty.
Tanzanite
Tanzanite is relatively new in the world of gemstones, but it has quickly gained a reputation for its calming and soothing properties. It is believed to promote emotional healing, balance, and inner peace. Tanzanite is associated with the heart and throat chakras, and it is often used in meditation and energy healing practices.
Tanzanite is also linked to creativity, intuition, and spiritual growth. It is believed to enhance one’s ability to access higher states of consciousness and to connect with the divine. The gemstone is considered a symbol of transformation and renewal, making it particularly relevant to December, a month of reflection and new beginnings.
Blue Zircon
Blue zircon is associated with clarity, focus, and spiritual awakening. It is believed to enhance one’s ability to think clearly and make wise decisions. Zircon is also linked to the heart and throat chakras, and it is often used in meditation to promote emotional healing and spiritual connection.
Zircon is considered a stone of transformation and renewal. It is believed to help individuals release old patterns and embrace new beginnings. The gemstone is also associated with protection and good fortune, making it a popular choice for those seeking to bring positivity and prosperity into their lives.
Care and Cleaning
Proper care and cleaning are essential for maintaining the beauty and longevity of the December birthstones.
Turquoise
Turquoise requires gentle handling due to its softness and porosity. It should be kept away from heat, chemicals, and excessive moisture. Cleaning can be done with a soft cloth and mild soap, followed by a gentle rinse with warm water. Ultrasonic and steam cleaners should be avoided, as they can damage the gemstone.
Turquoise jewelry should be stored separately to prevent scratches and abrasions. It is also advisable to avoid wearing turquoise during activities that involve physical contact or exposure to harsh substances.
Tanzanite
Tanzanite is sensitive to high temperatures and chemical exposure. It should be cleaned with warm, soapy water and a soft cloth. Ultrasonic and steam cleaners are not recommended, as they can cause damage to the gemstone.
Tanzanite jewelry should be stored in a cool, dry place to prevent exposure to extreme temperatures and humidity. It is also advisable to avoid wearing tanzanite jewelry during activities that involve physical contact or exposure to harsh chemicals.
Blue Zircon
Blue zircon is relatively durable and can be cleaned with warm, soapy water and a soft cloth. Ultrasonic and steam cleaners can be used with caution, but it is best to follow the manufacturer’s recommendations.
Zircon jewelry should be stored in a cool, dry place to prevent exposure to extreme temperatures and humidity. It is also advisable to avoid wearing zircon jewelry during activities that involve physical contact or exposure to harsh chemicals.
Conclusion
December’s birthstones — turquoise, tanzanite, and blue zircon — offer a diverse and beautiful selection for jewelry and personal adornment. Each gemstone has its own unique history, geological properties, and symbolic meaning, making them a meaningful choice for those born in this month. Whether you are a gemstone enthusiast, a jewelry buyer, or a student of gemology, these stones provide a fascinating glimpse into the intersection of science, culture, and art.
The tradition of birthstones continues to evolve, reflecting the changing tastes and discoveries of the modern world. As we celebrate December and its associated gemstones, we are reminded of the enduring appeal of these precious stones and their ability to connect us to our past, present, and future.