December, the final month of the year, is rich in symbolism and tradition. It is a time of celebration, reflection, and the anticipation of new beginnings. Among the many cultural and historical symbols associated with December, its birthstones stand out as particularly significant. Unlike months that have a single birthstone, December is uniquely associated with three: turquoise, tanzanite, and zircon—with blue zircon being the most commonly recognized. These gemstones have a long and storied history, evolving in significance over time and across cultures. This article delves into the rich tapestry of December’s birthstones, exploring their historical roots, geological properties, and their roles in both the spiritual and practical realms.
History and Lore of December Birthstones
The tradition of birthstones dates back to ancient times, with some of the earliest references found in the Bible’s Book of Exodus, which lists twelve gemstones for the twelve tribes of Israel. These were later associated with the months of the year during the Roman era, forming the foundation of the modern birthstone calendar. Over the centuries, the list of birthstones has evolved, with changes reflecting cultural, commercial, and scientific influences.
December, as it turns out, has had the most dynamic list of birthstones among all months. In ancient times, ruby was designated as the December birthstone. This red gemstone was believed to sharpen the mind, improve concentration, and encourage courtly love. The ruby's prominence in early lists reflects its high status in the ancient world, where it was considered a symbol of power and nobility.
However, by the 19th century, the birthstone for December had changed significantly. In 1870, turquoise was included in the list by Tiffany & Co. in their "Gregorian Birthstone Poems" pamphlet. This was followed in 1912 by the National Association of Jewellers (now the Jewelers of America), who listed turquoise as the primary December birthstone and lapis lazuli as an alternative. Lapis lazuli, a gemstone of ancient royalty and artists, had been revered for its deep blue color and golden flecks, often used in jewelry and decorative arts.
In 1952, the Jewelry Industry Council of America added zircon to the list of December birthstones. Zircons, particularly blue zircons, became popular for their vibrant color and brilliance. Zircon’s inclusion marked a shift toward more diverse and affordable options in the birthstone tradition.
Then, in 2002, tanzanite was officially added to the December birthstone list in the United States. Tanzanite, a relatively modern discovery found only in Tanzania, quickly gained popularity for its stunning blue-violet hues. Its addition highlighted the changing nature of the birthstone tradition, influenced by the availability of new gemstones and their growing appeal in the jewelry market.
The inclusion of multiple birthstones for December reflects the evolving nature of the tradition. It allows for a wider range of options, accommodating different styles, budgets, and personal preferences. This flexibility is one of the reasons December birthstones are particularly diverse and rich in meaning.
Geological Formation and Sources of December Birthstones
Understanding the geological formation and sources of December’s birthstones provides insight into their rarity, beauty, and value. Each gemstone has a unique origin story, shaped by the Earth’s dynamic processes over millions of years.
Turquoise
Turquoise is a mineral composed of copper aluminum phosphate. It forms in arid regions where water percolates through copper ore deposits, a process that can take thousands of years. The interaction of acidic copper-carrying water with aluminum and potassium in surrounding rocks leads to the formation of turquoise. This gemstone is typically found in weathered volcanic rock and sedimentary rock, often in areas with a history of copper mining.
The most well-known sources of turquoise include the American Southwest, particularly the Arizona and Nevada regions, as well as China, Egypt, and Iran. Turquoise from these regions often has a distinctive coloration, with greenish tones being more common in Chinese turquoise and blue tones more prevalent in American and Egyptian turquoise. The presence of matrix patterns—the dark veins that run through the stone—can also vary by location, influencing the stone's visual appeal and value.
Tanzanite
Tanzanite is a relatively recent discovery in the gemstone world, first identified in Tanzania in the 1960s. It is a variety of the mineral zoisite, and its striking blue-violet color is the result of a unique geological process involving the presence of vanadium. Tanzanite is found only in the Merelani Hills near Arusha, Tanzania, making it one of the rarest gemstones in the world. The limited supply and the stone’s vivid color have contributed to its rapid rise in popularity.
Tanzanite is formed under high-pressure conditions, typically in metamorphic rock environments. The transformation of zoisite into tanzanite requires specific geological conditions, including the presence of vanadium and the right temperature and pressure levels. The fact that tanzanite is found only in one location in the world adds to its mystique and value.
Zircon
Zircon is a zirconium silicate mineral that occurs in a wide range of colors, including blue, yellow, red, and green. The blue zircons that are most commonly associated with December are the result of heat treatment, a process that enhances the natural color of the stone. Zircon is found in various parts of the world, including Sri Lanka, Australia, Myanmar, Vietnam, and Cambodia.
Zircon forms in a variety of geological environments, including igneous and metamorphic rocks. It is often found in granite and sedimentary rocks, where it can remain stable for billions of years. The Mohs hardness of zircon ranges from 6 to 7.5, making it relatively durable, though it is more susceptible to abrasion than harder gemstones like diamond or ruby. Some zircons are also known to exhibit radioactivity, a property that has been studied for its potential applications in geochronology and nuclear science.
Gemological Properties of December Birthstones
The gemological properties of December’s birthstones—turquoise, tanzanite, and zircon—are what make them unique and valuable. Each gemstone has distinct characteristics that influence its appearance, durability, and care requirements.
Turquoise
Turquoise is a relatively soft gemstone, with a Mohs hardness of 5 to 6. This means it is more susceptible to scratches and damage than harder gemstones like diamond or sapphire. Its porous nature also makes it prone to discoloration from oils, lotions, and other substances. Turquoise is typically opaque or semi-translucent and is known for its vibrant blue and green colors, often with matrix patterns that add to its visual appeal.
One of the most distinctive features of turquoise is its chemical composition, which includes copper and aluminum phosphate. This composition gives turquoise its characteristic color and makes it sensitive to changes in its environment. For example, turquoise can lose moisture and change color if exposed to dry conditions for extended periods. This sensitivity means that turquoise jewelry should be handled with care and stored in a humid environment to prevent drying out.
Tanzanite
Tanzanite has a Mohs hardness of 6 to 7, making it more durable than turquoise but still relatively soft compared to other gemstones. Its trichroic nature—the ability to display three different colors depending on the angle of light—is one of its most fascinating features. Tanzanite typically exhibits a blue-violet color, but it can also appear deep blue or reddish brown under different lighting conditions.
Tanzanite is a trigonal mineral, meaning its crystal structure is not symmetrical in all directions. This can affect its cleavage, making it more susceptible to breaking along specific planes. As a result, tanzanite is best suited for low-wear jewelry, such as pendants and earrings, rather than rings or bracelets, where it is more likely to be subjected to impact or abrasion.
Zircon
Zircon has a Mohs hardness ranging from 6 to 7.5, making it one of the harder gemstones among December’s birthstones. However, its brittle nature means it can chip or crack if subjected to sudden impact. Zircon is also known for its high refractive index, which gives it a sparkling, fire-like appearance. This makes zircon a popular choice for jewelry that requires a bright, eye-catching gemstone.
Zircon occurs in a wide range of colors, including blue, yellow, red, green, and brown. The blue zircons most commonly associated with December are typically the result of heat treatment, a process that enhances the natural color of the stone. Zircon is also known for its strong dispersion, which means it can produce a rainbow of colors when light passes through it, similar to a diamond.
Symbolism and Metaphysical Beliefs
Throughout history, gemstones have been attributed with various spiritual, emotional, and metaphysical properties. These beliefs often vary by culture and era, but they share a common thread: the idea that gemstones can influence the mind, body, and spirit.
Turquoise
Turquoise has long been associated with protection, prosperity, and good fortune. In ancient times, it was considered a talisman of protection, especially in cultures that valued its deep blue color as a symbol of the sky and the sea. Shamans and spiritual leaders often used turquoise in rituals, believing it to connect the physical and spiritual worlds.
In more recent times, turquoise has been associated with calmness and emotional balance. It is believed to help soothe the mind, reduce stress, and promote a sense of inner peace. In some cultures, turquoise is also associated with healing and vitality, making it a popular choice for those seeking emotional and physical well-being.
Tanzanite
Tanzanite is often associated with spiritual growth, emotional healing, and transformation. Its deep blue-violet color is believed to resonate with the third eye and crown chakras, centers of intuition and spiritual awareness. Tanzanite is said to help open the mind to new ideas, encourage self-reflection, and support emotional healing.
Some believe that tanzanite can help individuals communicate their inner truths, especially those related to love, compassion, and understanding. It is also considered a stone of protection, particularly against emotional pain and negative energy. Tanzanite is often used in meditation and energy work, where it is believed to enhance spiritual connection and inner clarity.
Zircon
Zircon is a gemstone with a long history of metaphysical significance. It is often associated with joy, emotional balance, and inner peace. In some traditions, zircon is believed to help release negative emotions, such as fear and anxiety, and promote a sense of happiness and optimism.
Blue zircon, in particular, is considered a stone of protection, offering emotional support and mental clarity. It is believed to help align the chakras, especially the heart and throat chakras, which are associated with love, communication, and emotional expression. Zircon is also thought to enhance creativity and intuition, making it a popular choice for those who seek to express themselves in meaningful ways.
Care and Cleaning of December Birthstones
Proper care and cleaning are essential for preserving the beauty and longevity of gemstones. Each December birthstone has specific care requirements based on its hardness, porosity, and sensitivity to light and chemicals.
Turquoise
Turquoise requires gentle handling due to its softness and porosity. It is best to avoid exposing it to oils, lotions, and other chemicals, as these can discolor or damage the stone. To clean turquoise, use a soft cloth and mild soap with warm water. Gently wipe the stone and avoid using abrasive materials or harsh chemicals.
Because turquoise is sensitive to drying out, it is important to store it in a humid environment, such as a jewelry box with a damp cloth or a sealed container with a piece of damp paper. This helps prevent the stone from losing its moisture and changing color over time.
Tanzanite
Tanzanite is relatively durable, but it is still sensitive to impact and abrasion. To clean tanzanite, use a soft brush and mild soap with warm water. Avoid using ultrasonic or steam cleaners, as these can cause the stone to crack or chip.
Because tanzanite is trichroic, it is best to avoid exposing it to prolonged sunlight, as this can alter its color. Store tanzanite in a dark, cool place to preserve its vibrant blue-violet hue. Avoid wearing tanzanite jewelry during physical activities or household tasks, as it is susceptible to impact.
Zircon
Zircon is harder than turquoise and tanzanite, but it is still brittle and prone to chipping. To clean zircon, use a soft brush and mild soap with warm water. Avoid using ultrasonic or steam cleaners, as these can damage the stone.
Because zircon is often heat-treated, it is important to avoid exposing it to high temperatures, as this can alter its color. Store zircon in a cool, dry place, and avoid wearing it during physical activities or household tasks to prevent chipping or cracking.
Conclusion
December’s birthstones—turquoise, tanzanite, and zircon—represent a rich and diverse tradition that has evolved over centuries. Each gemstone has a unique geological origin, historical significance, and metaphysical meaning, making them valuable not only as jewelry but also as symbols of protection, transformation, and emotional balance. Whether you are drawn to the calming blue of turquoise, the vibrant violet of tanzanite, or the sparkling brilliance of zircon, December’s birthstones offer something for every taste and style. Understanding their properties, history, and care requirements ensures that these beautiful gems can be enjoyed for generations to come.