December, the final month of the year, is symbolically rich with celebration and introspection. Its name, derived from the Latin decem meaning “ten,” originally marked it as the tenth month in the ancient Roman calendar. As the coldest and darkest month in the northern hemisphere, December has historically been associated with transformation, renewal, and the coming together of loved ones during holidays such as the Winter Solstice, Christmas, Hanukkah, Kwanzaa, and New Year’s Eve. In this spirit of change and connection, December is also marked by a unique tradition: the celebration of multiple birthstones.
What sets December apart from other months is that it is one of the few with three to four officially recognized birthstones, each with its own distinct history, symbolism, and gemological profile. These include Turquoise, Blue Topaz, Zircon (especially Blue Zircon), Tanzanite, and in older traditions, Ruby, Lapis Lazuli, and Chrysoprase. This diversity reflects both the evolution of birthstone lore and the cultural and scientific discoveries that have expanded our understanding of gemstones over time.
This article explores the gemological, historical, and cultural significance of each of these stones, providing a comprehensive overview of what makes December's birthstones so special. Whether you are a jewelry buyer, a gemstone enthusiast, or a student of gemology, you will find detailed insights into the properties, meanings, and care of these captivating stones.
History and Lore of December Birthstones
The concept of birthstones has ancient roots, often tied to religious, cultural, and astrological traditions. The earliest recorded birthstone lists date back to the Bible, specifically the Book of Exodus, which describes the High Priest’s Breastplate adorned with twelve gemstones representing the twelve tribes of Israel. Over time, these biblical stones were matched with the months of the year, forming the basis for the modern birthstone tradition.
December, in particular, has undergone significant changes in its list of associated gemstones. According to historical records:
Ruby was the December birthstone in ancient times. This deep red gemstone was believed to sharpen the mind, improve concentration, and inspire courtly love. It was a symbol of nobility and passion, favored by royalty and mystics alike.
Lapis Lazuli was considered a December birthstone prior to 1950. A stone of ancient royalty and artists, Lapis Lazuli was prized for its deep blue color and golden flecks of pyrite. It was associated with self-mastery, protection, and the calming of the mind.
Turquoise, by contrast, has been a December birthstone for thousands of years. In ancient Egypt, turquoise was considered a protective and healing stone. Pharaohs and other rulers wore it to symbolize power, health, and divine favor. In China, artisans carved turquoise over 3,000 years ago. It was also revered by Native American tribes for its spiritual significance and was believed to bring good fortune.
Zircon entered the December birthstone list in 1952. While less well-known than some other gemstones, zircon offers a range of colors, with blue zircon being the most commonly associated with December. It is believed to promote emotional balance and joy.
Tanzanite became an official December birthstone in 2002. Discovered in Tanzania in 1967, tanzanite is a rare and vibrant blue-violet gemstone. It is known for its soothing energy and its ability to help individuals express spiritual insights from the heart.
The evolution of December’s birthstone list reflects broader shifts in both gemology and cultural trends. From the ancient association with ruby to the modern embrace of tanzanite and zircon, each stone carries its own unique legacy and meaning.
Geological Formation and Sources
Understanding the geological origins of December's birthstones provides valuable insight into their rarity, durability, and aesthetic qualities. Each of these stones forms under specific conditions, resulting in a wide variety of colors and properties.
Turquoise
Turquoise is a phosphate mineral composed of copper, aluminum, and phosphorus. Its formation occurs when acidic, copper-rich water percolates through weathered copper ore deposits, particularly in arid regions. The interaction between copper, aluminum, and other minerals in the rock leads to the precipitation of turquoise in cavities and fractures within volcanic and sedimentary rocks.
Key sources of turquoise include:
- Nevada, USA: Known for its high-quality “Nevada blue” turquoise.
- Iran (Persia): The source of the famous “Persian turquoise,” prized for its rich blue color and minimal matrix.
- China, Russia, and Egypt: Also have historical and modern turquoise deposits.
Turquoise is relatively soft, with a Mohs hardness of 5–6, and is porous, making it susceptible to scratches, stains, and dehydration. It often contains matrix patterns—natural veins of the surrounding rock—which can enhance its appearance.
Blue Topaz
Topaz is a silicate mineral with the chemical formula Al₂SiO₄(F,OH)₂. Natural blue topaz is rare; most blue topaz is created through heat treatment or irradiation of colorless or brown topaz. This treatment alters the crystal structure, resulting in a range of blue tones from sky blue to deep London blue.
Key sources of topaz include:
- Brazil: The primary global producer of topaz, including blue topaz.
- United States, Mexico, and Nigeria: Also contribute to topaz production.
Topaz is very hard, with a Mohs hardness of 8, making it durable and resistant to scratches. It is stable under normal conditions but should be protected from sharp blows and sudden temperature changes.
Zircon
Zircon is a zirconium silicate with the chemical formula ZrSiO₄. Naturally occurring zircon often has a brown or reddish color, but it can be heat-treated to produce blue, colorless, yellow, and even rainbow-colored stones. Blue zircon is especially popular as a December birthstone.
Key sources of zircon include:
- Sri Lanka and Thailand: Known for producing high-quality zircon.
- Australia, Myanmar, and Cambodia: Additional sources of zircon.
Zircon has a Mohs hardness of 6–7.5, which makes it moderately durable, though it can fracture if subjected to impact. It is also sensitive to prolonged exposure to light, as some heat-treated varieties may revert to their original color.
Tanzanite
Tanzanite is a trigonal mineral and a trichroic gemstone, meaning it exhibits three different colors when viewed from different angles. Its chemical formula is CaAl₆SiO₁₂(OH)₁₂, and it forms under specific geological conditions involving the cooling of metamorphic rocks in Tanzania.
Key source: Tanzania is the only place in the world where tanzanite is found, making it one of the rarest gemstones on Earth.
Tanzanite has a Mohs hardness of 6–7, and like zircon, it is sensitive to heat and light. Prolonged exposure to sunlight or high temperatures can cause it to fade or lose its color.
Gemological Properties of December Birthstones
The gemological properties of a stone—such as its hardness, color, clarity, refractive index, and chemical composition—are essential for understanding its durability, value, and suitability for jewelry. Below is a comparison of the key gemological characteristics of the December birthstones:
| Gemstone | Chemical Formula | Mohs Hardness | Color Variations | Refractive Index | Transparency | Durability Notes |
|---|---|---|---|---|---|---|
| Turquoise | CuAl₆(PO₄)₄(OH)₈·4H₂O | 5–6 | Blue, green, with matrix | 1.61–1.65 | Opaque | Porous; sensitive to stains and dryness |
| Blue Topaz | Al₂SiO₄(F,OH)₂ | 8 | Sky blue, London blue | 1.61–1.63 | Transparent | Very durable; avoid sudden temperature changes |
| Blue Zircon | ZrSiO₄ | 6–7.5 | Blue, colorless, yellow | 1.92–2.00 | Transparent | Sensitive to light; can fade |
| Tanzanite | CaAl₆SiO₁₂(OH)₁₂ | 6–7 | Blue-violet (trichroic) | 1.69–1.70 | Transparent | Sensitive to heat and UV light |
These properties influence how each gemstone is used in jewelry, how it should be cleaned and maintained, and how valuable it is in the market.
Symbolism and Metaphysical Beliefs
December’s birthstones have long been associated with spiritual, emotional, and physical well-being. These associations vary across cultures and time periods, but common themes include protection, healing, emotional balance, and spiritual growth.
Turquoise
Turquoise has been revered for its protective and healing properties for thousands of years. Ancient Egyptians believed it could ward off disease and misfortune, while Native Americans used it in ceremonies and as a symbol of wisdom and health. It is also associated with honesty, communication, and emotional clarity.
Blue Topaz
Blue topaz is often linked to calmness, wisdom, and spiritual alignment. It is believed to stimulate self-esteem, enhance learning, and aid in meditation. In some traditions, it is considered a stone of serenity and inner peace.
Zircon
Zircon is associated with joy, emotional balance, and mental clarity. It is considered a stone of transformation, helping individuals navigate emotional challenges and embrace new perspectives.
Tanzanite
Tanzanite is often described as a stone of spiritual awakening and emotional healing. It is believed to help individuals express their inner truths, especially from the heart, and to facilitate communication with spiritual guides.
Care and Cleaning of December Birthstones
Proper care is essential for preserving the beauty and integrity of December’s birthstones. Each stone has unique cleaning and maintenance requirements based on its hardness, porosity, and sensitivity to light and chemicals.
Turquoise
- Soft and porous, turquoise requires gentle handling.
- Avoid exposure to moisture, oils, and acidic substances.
- Clean with a soft cloth and a mild soap solution.
- Store in a sealed container with a damp cloth to prevent drying out.
Blue Topaz
- Very hard and durable, blue topaz can be cleaned with warm water and mild soap.
- Use a soft brush to remove dirt.
- Avoid exposure to sudden temperature changes.
Blue Zircon
- Zircon is moderately hard but sensitive to light.
- Clean with a soft brush and mild soap.
- Avoid ultrasonic or steam cleaners, as they may damage heat-treated stones.
- Store in a dark place to prevent fading.
Tanzanite
- Tanzanite should be handled with care due to its sensitivity to heat and light.
- Clean with a soft brush and mild soap.
- Avoid exposure to direct sunlight for long periods.
Conclusion
December's birthstones offer a fascinating blend of beauty, history, and symbolism. From the ancient reverence for ruby and lapis lazuli to the modern popularity of tanzanite and zircon, these gemstones reflect the evolving understanding of gemology and the enduring appeal of natural treasures.
Each December birthstone—whether turquoise, blue topaz, zircon, or tanzanite—carries its own unique energy, meaning, and aesthetic. Whether you are drawn to the deep blue of turquoise, the bright clarity of blue topaz, the vibrant hues of zircon, or the rare and mystical allure of tanzanite, there is a December birthstone that resonates with your personality and style.
Understanding the geological origins, cultural significance, and care requirements of these stones allows you to cherish and preserve them for generations to come. Whether you choose to wear them as jewelry, collect them as specimens, or study them as part of a gemological collection, December’s birthstones are a testament to the beauty and power of the natural world.