December, the final month of the year, is uniquely represented by a rich tapestry of gemstones—five in total, each with its own distinct hue, historical lineage, and symbolic significance. Unlike months that typically feature a single birthstone, December boasts multiple gemstones: Blue Zircon, Blue Topaz, Tanzanite, Lapis Lazuli, and Turquoise. This diverse selection reflects the month’s association with transformation, celebration, and the convergence of winter solstice, Christmas, and New Year’s Eve. These stones have evolved from ancient symbols of power and protection to modern-day emblems of personal expression and beauty.
In this article, we explore the origins, properties, and cultural meanings of each December birthstone, offering a comprehensive guide for gemstone enthusiasts, jewelry buyers, and students of gemology. We will examine the historical evolution of December's gemstone list, the scientific properties that define these stones, and the metaphysical beliefs that have shaped their use through the ages. Additionally, we will discuss how these gemstones are sourced, cared for, and incorporated into contemporary jewelry.
History and Lore
The tradition of associating gemstones with months of the year dates back centuries, with roots in both religious and cultural practices. The earliest known references to birthstones come from the Biblical Book of Exodus, where a list of twelve stones is described as part of the High Priest’s Breastplate. These stones were believed to represent divine power and were used to channel spiritual energy. In these early lists, Ruby was designated for December, symbolizing passion, courage, and vitality.
However, the modern concept of birthstones began to evolve in the 19th century. In 1870, Tiffany & Co. published a pamphlet titled “Gregorian Birthstone Poems,” which listed Turquoise as the birthstone for December. This marked the beginning of a more secular and commercial interpretation of birthstones, shifting the focus from spiritual significance to aesthetic and symbolic value.
By 1912, the National Association of Jewellers (now known as Jewellers of America) expanded the list, designating Turquoise as the primary December birthstone and Lapis Lazuli as an alternative. This was followed by the 1952 addition of Zircon, particularly Blue Zircon, by the Jewelry Industry Council of America. In 2002, Tanzanite was officially added to the list, marking a significant modernization of the December birthstone tradition.
This evolution reflects changing cultural preferences and the availability of new gemstones. Turquoise, Lapis Lazuli, and Zircon were once the dominant choices, while Tanzanite and Blue Topaz have become more prominent in contemporary times. Each of these stones carries its own unique history and symbolism, contributing to the rich and varied heritage of December’s birthstone tradition.
Geological Formation and Sources
The geological origins of December’s birthstones are as diverse as the stones themselves. Each gemstone forms under specific conditions and is found in distinct locations around the world.
Turquoise
Turquoise is a hydrated phosphate of aluminum and copper, with the chemical formula Al₂(OH)₃PO₄·nH₂O. It forms in the oxidation zones of copper deposits, typically in arid regions where water is present. Turquoise is known for its vivid blue and green hues, which are caused by the presence of copper and iron, respectively.
Historically, the most significant source of turquoise was Persia (modern-day Iran), from where it was exported to Europe and the Middle East. In the Americas, Native American tribes in the Southwestern United States were known for their use of turquoise in jewelry and ceremonial objects. Today, major sources of turquoise include Iran, China, the United States (especially Nevada and New Mexico), and Egypt.
Blue Zircon
Zircon is a silicate mineral with the chemical formula ZrSiO₄. It is known for its high refractive index and dispersion, which gives it a brilliant fire similar to diamond. Zircon occurs in a wide range of colors, from colorless and brown to vibrant blue and green.
The blue coloration in Blue Zircon is the result of a heat treatment process that removes impurities and alters the crystal structure. Zircon is found in various parts of the world, including Australia, Brazil, Cambodia, and India. In the context of December birthstones, Blue Zircon has become a popular alternative to Blue Topaz, offering a more affordable and versatile option for jewelry.
Blue Topaz
Topaz is a silicate mineral with the chemical formula Al₂SiO₄(F,OH)₂. In its natural form, topaz is colorless, but it can occur in a range of colors, including yellow, orange, pink, and blue. The blue color in Blue Topaz is typically the result of irradiation and heat treatment, which alters the stone’s internal structure.
Natural blue topaz is rare, and most of the blue topaz available in the market is enhanced. The most significant sources of topaz include Brazil, Mexico, Russia, and Sri Lanka. Blue Topaz is prized for its clarity and affordability, making it a popular choice for December birthstone jewelry.
Tanzanite
Tanzanite is a variety of the mineral columbite-zircon, with the chemical formula Ca₂Al₃(SiO₄)₃(OH). It is known for its striking blue to violet color, which is caused by the presence of trace elements such as vanadium. Tanzanite was first discovered in Tanzania in 1967, near Mount Kilimanjaro, and it remains the only known source of this gemstone.
The unique color of tanzanite is due to the way it absorbs and reflects light. It is also pleochroic, meaning it can display different colors when viewed from different angles. Tanzanite is relatively soft compared to other December birthstones, with a Mohs hardness of 6 to 7, which means it requires careful handling to avoid scratches and damage.
Lapis Lazuli
Lapis Lazuli is not a single mineral but a rock composed of several minerals, primarily lazurite, which gives it its characteristic deep blue color. Other components include calcite and pyrite, which add white and golden flecks to the stone. Lapis Lazuli has been used for thousands of years in jewelry, amulets, and decorative objects.
The most significant historical source of lapis lazuli is the Badakhshan region in Afghanistan, where it has been mined for over 6,000 years. Today, lapis lazuli is also found in Russia, Canada, and the United States, but the finest quality stones continue to come from Afghanistan.
Gemological Properties
Each of December’s birthstones has unique gemological properties that influence their use in jewelry and their care requirements.
| Gemstone | Chemical Formula | Hardness (Mohs) | Refractive Index | Transparency | Common Color(s) |
|---|---|---|---|---|---|
| Turquoise | Al₂(OH)₃PO₄·nH₂O | 5–6 | 1.61–1.65 | Opaque | Blue, Green |
| Blue Zircon | ZrSiO₄ | 6–7.5 | 1.92–2.00 | Transparent | Blue |
| Blue Topaz | Al₂SiO₄(F,OH)₂ | 8 | 1.61–1.63 | Transparent | Blue |
| Tanzanite | Ca₂Al₃(SiO₄)₃(OH) | 6–7 | 1.69–1.70 | Transparent | Blue to Violet |
| Lapis Lazuli | Lazurite (Na,Ca)Al₆Si₆O₂₀(S,Cl,S) | 5–6 | 1.5–1.7 | Opaque | Deep Blue with golden flecks |
Turquoise
Turquoise has a hardness of 5–6 on the Mohs scale, making it relatively soft and prone to scratches and abrasions. It is also porous, which means it can absorb oils and dirt over time. Due to its opacity, it is typically cut into cabochons rather than faceted stones.
Blue Zircon
Blue Zircon has a hardness of 6–7.5, which makes it more durable than turquoise. It has a high refractive index, which contributes to its brilliance and fire. Blue Zircon is often faceted to maximize its optical properties.
Blue Topaz
Blue Topaz is one of the hardest December birthstones, with a hardness of 8 on the Mohs scale. It is also relatively stable and can be exposed to light and heat without significant color change. This makes it ideal for everyday wear in jewelry.
Tanzanite
Tanzanite has a hardness of 6–7, which means it requires careful handling to avoid scratches and chips. It is pleochroic, displaying different colors when viewed from different angles. Tanzanite is also sensitive to heat, and exposure to high temperatures can cause it to lose its color.
Lapis Lazuli
Lapis Lazuli is a rock and not a single mineral, which means its hardness varies depending on the components present. It typically has a hardness of 5–6, making it soft and prone to scratches. It is opaque and is usually cut into cabochons or used for inlays and mosaics.
Symbolism and Metaphysical Beliefs
December’s birthstones have long been associated with various symbolic meanings and metaphysical properties. These beliefs have evolved over time and are influenced by cultural traditions, historical uses, and modern interpretations.
Turquoise
Turquoise has been revered for its protective and healing properties for thousands of years. In ancient cultures, it was believed to offer protection from harm, good fortune, and spiritual clarity. It was also used in ceremonial objects and jewelry to symbolize wisdom, truth, and harmony.
Blue Zircon
Blue Zircon is associated with joy, emotional balance, and spiritual clarity. It is believed to help calm the mind, enhance focus, and promote inner peace. In some traditions, Blue Zircon is also used for manifesting positive intentions and fostering emotional healing.
Blue Topaz
Blue Topaz is often linked to calmness, serenity, and emotional stability. It is believed to help release fear and anxiety, encourage self-expression, and support mental clarity. It is also associated with good fortune, love, and spiritual awakening.
Tanzanite
Tanzanite is associated with spiritual transformation, emotional healing, and intuitive development. It is believed to help open the heart, encourage compassion, and foster a deeper connection to the divine. Tanzanite is also used for meditation and energy work due to its soothing and grounding properties.
Lapis Lazuli
Lapis Lazuli has long been associated with wisdom, truth, and self-mastery. It was used by ancient royalty and artists as a symbol of intellectual power and spiritual insight. In modern times, it is believed to help reduce stress, enhance self-awareness, and promote emotional balance.
Care and Cleaning
Proper care is essential to maintaining the beauty and longevity of December’s birthstones. Each gemstone has specific care requirements based on its hardness, porosity, and sensitivity to light and heat.
Turquoise
Turquoise is porous and sensitive to oils and dirt, so it should be cleaned gently with a soft cloth and warm, soapy water. It should be avoided exposure to harsh chemicals, extreme temperatures, and prolonged sunlight, as these can cause it to fade or crack.
Blue Zircon
Blue Zircon is relatively durable, but it should still be cleaned carefully. It can be cleaned with warm, soapy water and a soft brush, but avoid ultrasonic cleaners, as they can damage the stone. It should also be stored separately from other gemstones to prevent scratches.
Blue Topaz
Blue Topaz is one of the most durable December birthstones, with a hardness of 8. It can be cleaned with warm, soapy water, a soft brush, or even an ultrasonic cleaner. It is resistant to fading and can be worn daily in jewelry.
Tanzanite
Tanzanite is sensitive to heat and light, so it should be cleaned gently with warm, soapy water and a soft cloth. It should avoid exposure to high temperatures, as this can alter its color. It should also be stored in a cool, dark place to prevent fading.
Lapis Lazuli
Lapis Lazuli is soft and porous, so it should be cleaned gently with a soft cloth and warm, soapy water. It should avoid exposure to harsh chemicals, heat, and prolonged sunlight, as these can damage the stone and cause it to fade.
Conclusion
December’s birthstones represent a unique and diverse collection of gemstones that reflect the month’s rich cultural and historical significance. From the ancient traditions of Ruby and Lapis Lazuli to the modern additions of Tanzanite and Blue Topaz, each stone offers a different hue, meaning, and story. These gemstones are not only beautiful but also deeply symbolic, carrying with them centuries of lore and spiritual significance.
Whether you are born in December or simply drawn to the allure of these stones, understanding their geological properties, historical context, and metaphysical meanings can enhance your appreciation and connection to these remarkable gems. As fine jewelry, December’s birthstones offer a versatile and meaningful way to express individuality, while also serving as a link to the past and a celebration of the present.
By choosing a December birthstone, you are not only selecting a beautiful gem but also embracing a piece of history, culture, and personal significance. These stones continue to evolve with time, just like the people who wear them, making them a perfect symbol of transformation and renewal.